Metaverse Architectures: A Comprehensive Systematic Review of Definitions and Frameworks

Abstract

The metaverse is a multidimensional reality space that represents the evolving interface between humans, digital systems, and spatial computing. This research aims to provide a comprehensive synthesis of metaverse definitions and architectural frameworks through the analysis of academic literature. A systematic literature review of 103 peer-reviewed studies was conducted, from which 33 explicit definitions and 25 architectural models were selected for detailed analysis. A mixed-methods qualitative approach was employed, combining a systematic literature analysis, word frequency analysis, and a thematic analysis to develop an expanded conceptual and architectural understanding. The analysis of 33 definitions revealed eight recurring conceptual themes, which were synthesised into five overarching categories: conceptual and linguistic constructs, spatial-environmental design, technological orientation, economic and governance systems, and social and human interaction. A total of 25 studies proposing architectural models are categorised into three thematic groups: technology-based, domain-based and layered architectures. A significant contribution of this study is the categorisation and comparative evaluation of foundational architectural models, specifically the extensively referenced three-, four-, and five-layer frameworks. The findings are structured around two primary areas of focus: the conceptual definition and the comparative analysis of established metaverse architecture models, focusing on a set of well-established models that exhibit conceptual clarity, structural coherence, and widespread acceptance in the literature. This integrated methodological approach not only offers a dual-perspective analysis that bridges conceptualisation and system design but also introduces an analytical framework that supports future standardisation and governance discussions.

1. Introduction

With the expansion of studies on three-dimensional (3D) mixed reality (MR), virtual reality (VR), and augmented reality (AR), the metaverse has garnered significant interest from various institutions and organisations worldwide, aiming to develop immersive environments and facilitate real-time communication through these technologies. The term “metaverse” was historically used by Neal Stephenson in the 1992 science-fiction novel Snow Crash, where people use virtual reality to access a shared digital world [1].

In its history, the metaverse has evolved from a theoretical concept to a pivotal element in the technology and entertainment industries. This evolution came from advances in online multiplayer gaming, VR, AR, and artificial intelligence [2]. Linden Lab [3] introduced the first virtual world with Second Life in 2003, and Roblox [4] launched in 2006 an online multi-user platform that allows users to create and play games developed by others. Another notable literary work that gained significant attention was Ernest Cline’s Ready Player One, published in 2011 and later adapted into a film [5]. The film portrayed a future in which individuals utilised haptic gloves and a VR headset to escape their mundane lives and enter a virtual world where they can experience tactile sensations [6]. Microsoft, Nvidia, and Meta subsequently introduced prototypes for the metaverse in 2021 [7]. Microsoft launched Mesh for Teams to enable immersive, mixed-reality communication in workplaces [8]. Similarly, NVIDIA introduced the Omniverse platform, designed to integrate 3D environments into a collective virtual reality [9]. Meanwhile, following its rebranding from Facebook, Meta launched Horizon Worlds, a virtual reality social platform designed to promote user engagement and collaborative content creation [10].

Currently, there is no consensus on the exact definition of the metaverse topology [11,12,13,14,15], as various interpretations exist, and hence, no standard definition has been established [16,17]. The absence of a unified definition of the metaverse stems from multiple interconnected factors, reflecting its dynamic nature and the diverse perspectives of stakeholders such as academics, technologists, and industry leaders [18,19]. Diverse individuals, institutions, and organisations define the metaverse according to their specific contexts and objectives, resulting in a multitude of definitions that reflect varying perspectives [20]. Consequently, scholars and industry professionals offer differing conceptualisations without a unified consensus [21,22]. For example, some view the metaverse primarily from a technological perspective, emphasising its infrastructure and functionalities, while others approach it philosophically, considering its societal implications and user experience [23,24]. Moreover, the complex nature of defining the metaverse stems from its broad scope, encompassing gaming, social interaction, economics, education, and other domains [25].

The definition of the metaverse is further complicated by its rapid advancement of enabling technologies and the continuous expansion of associated domains [26]. These technologies are essential systems that underpin the creation and functioning of the metaverse, enhancing immersive user experiences that integrate physical and virtual environments [27]. The enabling technologies include artificial intelligence (AI), blockchain, cloud computing, digital twins, and advanced network infrastructure like 5G. Blockchain functions as a decentralised, transparent, traceable, auditable, secure, and trustworthy digital ledger of transactions that can safeguard digital assets in the metaverse [28].

Artificial intelligence provides advanced services, including natural language processing, image recognition, recommendation systems, and virtual customer support, collectively enhancing user experience and interaction efficiency within the metaverse [29,30]. Cloud computing facilitates the metaverse by ensuring continuous, rapid processing, reducing complexity, and decreasing power consumption [31]. Digital twins [32], which are digital replicas of real-world objects or systems, facilitate the modelling and analysis of actual phenomena, thereby enhancing the realism and functional complexity of metaverse experiences. 5G technology plays a crucial role in enabling the development and functionality of the metaverse and its associated applications [33]. The 5G network offers the necessary reliability, throughput, and latency, which are critical requirements for the metaverse [34].

Current technological advances and human behaviour shape the conceptualisation and definition of the metaverse [21,35]. For example, the development of immersive hardware and the rise of 6G-enabled infrastructure are significantly shaping how the metaverse is conceptualised, enabling real-time, multisensory virtual experiences that blur the boundary between digital and physical worlds [23]. In parallel, changing human behaviours, such as increased virtual socialisation, demand for immersive experiences, and the normalisation of remote presence, are further driving the evolution of its definition [24]. However, the lack of agreement regarding the technologies that define the metaverse leads to definitional uncertainty, highlighting the necessity for a more precise conceptual framework in both academic and practical contexts [36].

The architectural form of the metaverse, much like its definition, is characterised by a lack of consensus due to the complexity and diversity of enabling technologies and its extensive range of applications [37]. The integration of diverse technologies, such as virtual reality, augmented reality, blockchain and artificial intelligence, necessitates distinct architectural requirements, each presenting specific design challenges [38]. Furthermore, the evolving nature of the metaverse contributes to the uncertainty in establishing a global framework. As these technologies advance, the foundational elements that define the metaverse continue to transform. The ecosystem is guided by short-term frameworks that respond to current conditions but may lack the capacity to provide the stability necessary for a comprehensive architectural standard [39]. Moreover, fundamental issues such as scalability and interoperability, inherent to the metaverse, further complicate security measures within its architecture [5,40,41].

The consideration of metaverse architecture is also complicated by conceptual disagreements among researchers and stakeholders. While some researchers promote centralised architectures with an emphasis on high-performance cloud computing to maintain sophisticated virtual environments, others support decentralised approaches that use blockchain technology to provide heightened security and privacy [36,42]. In addition, the lack of a shared terminology and comprehensive discourse on the building blocks of metaverse architecture also contributes towards disparate interpretations on metaverse architecture, thus denoting potential shortcomings within current literature and concerted research attempts [43].

In addition, the industry-specific use cases of the metaverse complicate the architectural landscape. Special requirements and functions demand specialised architectural frameworks designed for particular environments [44,45]. For example, a metaverse platform has been developed to support the preservation of intangible cultural heritage [46], while another conceptual framework has been proposed to transform cardiovascular healthcare through immersive technologies [47]. As a result, numerous architectures have emerged, each addressing different needs, yet none have achieved global acceptance [48,49,50].

The following parts of this paper are structured as follows. The methodology for identifying and analysing metaverse definitions and architectures through a systematic literature review and hybrid thematic analysis is detailed in Section 2. The results of this analysis are presented in Section 3, including the thematic synthesis of metaverse definitions and the classification of architectural models. Section 4 discusses the synthesised metaverse definitions and provides a comparative evaluation of prominent architectural frameworks. In conclusion, Section 5 summarises the key findings, limitations, and future research directions.

Contributions

The topic of the metaverse has attracted considerable research attention. To date, several papers have emerged from various aspects of the metaverse. For example, Ritterbusch and Teichmann [21] conducted a comprehensive review of existing literature, suggesting definitions that emphasised 3D environments and the convergence of technologies. Ng [36] identified decentralisation, immersion, and shared environments as key components. Zhou et al. [35] developed a framework that highlighted the evolving social and technological aspects of the metaverse. Cheng et al. [51] employed a methodology to identify key themes in a large text corpus, highlighting important metaverse characteristics such as collaboration, synchronisation, and the integration of real and virtual elements. Similarly, Almoqbel et al. [52] and Gao et al. [53] conducted reviews that revealed differences in academic definitions while also identifying common concepts such as user engagement, content creation, and effects on cognitive processes. Weinberger [54] defined the metaverse by emphasising interconnected virtual worlds, immersion, scalability, and economic infrastructure.

On the other hand, some academic studies have mostly focused on key requirements, describing the architectural infrastructure of the metaverse and closely examining its technical and design aspects. Rawat and El Alami [41] present a comprehensive overview of the Metaverse, including its requirements, architecture, and standards, as well as its challenges, open problems, and perspectives. Park and Kim [55] discuss the taxonomy of technologies in the metaverse, classifying the Metaverse components and major approaches into hardware, software, content, user interaction, implementations, and applications. Some articles [5,56,57] explored focus on enabling technologies and general architecture in the metaverse. Moreover, Raad and Rashid [58] report on the latest applications of the metaverse technology, concerns and technical challenges. Those papers primarily focused on an overview of the metaverse, its requirements, technologies, and proposed architecture; however, they lacked a unified architecture and a domain-agnostic framework that systematically integrates interoperability, governance, privacy, and technological scalability.

This research critically examines the definition and architectural conceptualisation of the Metaverse within academic literature. Addressing the persistent lack of consensus regarding both its definition and architecture, this study employs a systematic literature review to synthesise existing scholarly perspectives. The primary contributions of this study are as follows:

• First, a systematic review of the literature is undertaken to investigate the definitions and architectural frameworks of the metaverse within academic research. This enables the synthesis of current definitions and the identification of various proposed architectural models, thereby establishing a fundamental comprehension of conceptual and structural patterns.
• Second, a word frequency and thematic analysis is conducted on 33 metaverse definitions, culminating in a refined, generalised definition. Based on prevailing viewpoints, these definitions are then categorised into five specific types: technological orientation, spatial-environmental design, social and human interaction, economic and ownership systems and conceptual and linguistic constructs.
• Third, 25 architectural models are analysed and subsequently categorised into layered-based, technology-based, and domain-based classifications. A comparative evaluation is then conducted on the prominent three-layer, four-layer, and five-layer general-purpose architectures to ascertain structural depth and thematic coverage.
• Finally, we critically assess the gaps and limitations in existing architectures, particularly the absence of dedicated governance mechanisms and limited support for interoperability in earlier models. These insights underscore the need for future metaverse systems that integrate technical, social, and regulatory dimensions.

2. Methodology

The methodology of this study integrated a mixed-methods approach, featuring a systematic literature review conducted in accordance with the PRISMA 2020 guidelines [59], alongside qualitative analyses, including word frequency analysis and thematic coding. The SLR provided a basis for the identification of metaverse definitions and architectural models within existing literature. The analytical methods then enabled a more profound comprehension of conceptual and structural elements.

2.1. Systematic Literature Review

A systematic literature review was undertaken to explore existing definitions and architectural models of the metaverse. Relevant studies were identified through the Google Scholar database, employing search terms including “Metaverse”, “Metaverse definition”, “Metaverse requirements”, and “Metaverse architecture”. To ensure relevance, only peer-reviewed articles published in English between 2013 and 2025 were considered.

The selection procedure is detailed

Table 1. Inclusion and exclusion criteria.

Inclusion Criteria	Exclusion Criteria
Peer-reviewed journal and conference papers	Non-peer-reviewed publications (e.g., blogs, magazines)
Published in English between 2013 and 2025	Non-English publications
Studies that propose or discuss definitions of the metaverse	Studies that mention the metaverse without defining or analysing it
Studies that propose or analyse metaverse architecture models	Studies that do not include architectural or structural discussion
Accessible full-text articles	Articles for which full text was not retrievable

, which outlines the inclusion and exclusion criteria, and Figure 1, which presents the screening process following PRISMA flow diagram guidelines [59]. A total of 237 records were initially identified. Following the removal of 6 duplicates and 7 records for other reasons (non-English language), 224 records were screened. After reviewing abstracts and titles, 202 reports were selected for retrieval, with 10 being non-retrievable (lack of full-text availability). A full-text review was conducted on 192 reports, leading to the exclusion of 89 studies that did not satisfy the inclusion criteria (absence of definition or architectural discussion).

From the 103 studies included in the final review, two focused subsets were extracted for thematic analysis. The first subset comprised 33 studies that contained explicit definitions of the metaverse. In this study, a metaverse definition is understood as a formal conceptualisation of the term “metaverse”, articulated with sufficient conceptual clarity to support thematic comparison. Studies were included in this subset based on the following criteria: (1) the presence of clearly defined conceptualisations of the metaverse, located in the abstract, introduction, or a dedicated definitional section; and (2) the inclusion of meaningful descriptive content, offering more than a passing reference. Studies that mentioned the term without further elaboration were excluded to ensure conceptual depth and analytical rigour.

The second subset consisted of 25 studies selected for architectural analysis. For this research, a metaverse architectural model is defined as a structured framework that outlines the components, layers, or mechanisms involved in the design, implementation, or operation of a metaverse system. Studies were included if they (1) proposed structured architectures, such as layered models, modular frameworks, or domain-specific system designs, and (2) described two or more functional components (e.g., infrastructure layer or virtual world). Moreover, models were not limited by application domain, as long as they were explicitly framed as metaverse architectures. Both subsets were analysed using the unified thematic framework developed in this study, allowing for a consistent conceptual interpretation across definitional and architectural perspectives.

2.2. Thematic Analysis

A hybrid thematic analysis was utilised to synthesise the conceptual definitions of the metaverse as presented in academic literature. This methodology integrated data-driven word frequency analysis with a comprehensive six-phase thematic analysis framework, as proposed by Braun and Clarke [60]. Word frequency analysis is used to identify key concepts, offering a quantitative analysis of frequently occurring terms [61]. Subsequently, thematic analysis explores the meanings of these terms, revealing underlying motivations, relationships, and conceptual groupings [60]. This approach enhances analytical rigour through triangulation and cross-validation, increasing the credibility of key themes [62]. Additionally, it enhances the generalisability of the results by connecting context-specific qualitative insights to broader trends identified in the literature [63]. The integration of these methods allows the research to capture both the measurable and interpretive aspects of metaverse definitions and architectures. Definitions were extracted from peer-reviewed studies identified through the systematic literature review.

2.2.1. Word Frequency Analysis

A word frequency analysis was conducted using NVivo, a software application intended for qualitative and mixed methods research [64]. Definitions were derived from peer-reviewed literature discovered by the systematic review. A word cloud (Figure 2) was created to illustrate frequently occurring phrases. Semantic filtering was implemented to improve relevance. Commonly encountered yet low-significance terms (e.g., “digital”, “world”, “space”) were omitted for their lack of specificity, whereas conceptually rich terms such as “virtual”, “interconnected”, “persistent”, “avatar”, and “immersive” were chosen as initial codes. Variants and synonyms were consolidated to enhance semantic consistency and more accurately represent fundamental concepts across definitions.

2.2.2. Thematic Analysis Approach

Braun and Clarke`s six-phase methodology was used to conduct the thematic analysis:

• Familiarising with the data: Engagement with the dataset involved perusing and revisiting the retrieved metaverse definitions. This phase facilitated a thorough understanding of the literature’s scope, terminology, and conceptual framework.
• Generation of initial codes: The initial codes were generated using a hybrid computational and manual approach. To begin, all 33 definitions were imported into NVivo for qualitative analysis. A word frequency query identified high-frequency lexical items across the corpus of definitions, revealing conceptually salient terms and phrases such as “immersive”, “avatar”, “persistence”, “virtual”, and interconnected.” To improve conceptual specificity, a semantic filtering step excluded high-frequency but low-relevance descriptors, including generic terms such as “digital”, “environment”, and “world.” This refinement enhanced analytical salience by isolating semantically rich vocabulary that reflected distinctive attributes of the metaverse. Each selected term was treated as an initial code and examined for both explicit semantic usage and underlying latent meaning. Conceptually similar codes were consolidated into unified constructs, and lexical variations were normalised to ensure internal consistency. The resulting preliminary codebook consisted of surface-level terms and abstracted conceptual codes, forming the basis for sub-theme generation in the next phase of analysis.
• Searching for themes: After developing the codebook, initial codes were grouped into sub-themes according to their conceptual similarity and contextual relevance. For instance, codes like “VR”, “AR”, “AI”, and “blockchain” were aggregated into a sub-theme pertaining to enabling technologies. This iterative approach involved constant comparison and refinement, guaranteeing that each sub-theme represented a distinct conceptual cluster relevant to the metaverse.
• Reviewing themes: Sub-themes were examined across the dataset to ensure internal consistency within themes and distinct demarcations between them. Definitions that did not conform to the evolving thematic framework were reassessed or categorised under updated themes.
• Defining and naming themes: Sub-themes were developed, designated, and subsequently synthesised into overarching themes that encompass the essential elements of the metaverse as articulated in the literature.
• Producing the report: The concluding themes were employed to construct a cohesive narrative and thematic representation of metaverse conceptualisation. Themes outlined in

  Table 2. Codes and themes identified from word cloud analysis.

  Keywords from Word Cloud Analysis	Codes	Sub-Themes	Themes
  Virtual, universe, mapping, interacting, real world, seamless, linking, platforms, environments	Integration, interaction, interoperability	Mapping of physical to virtual, cross-platform interaction, real-virtual transitions	Interconnectivity
  VR, AR, AI, blockchain, real-time communication	Technology-driven, emerging tools	AI-driven personalisation, blockchain-based security	Technology enablers
  Immersive, 3D, shared	Immersion	Sensory-rich experiences, multi-sensor interaction	Immersion
  Persistent, perpetual, enduring	Continuity, persistence	Long-term data retention, stable virtual worlds	Persistence
  Avatars, collaboration, social connections, shared spaces	User representation, social interaction	Avatar-driven interaction, community-building	Social Engagement
  Activities, gaming, creation, trading, entertainment	Diverse activities, value creation	Collaborative creation, virtual trade and commerce	Multidimensional Activities
  Digital reality, real-world representation, mapping	Embodiment, representation	Digital twins, enhanced real-world simulations	Representation of Reality
  Trading, economy, monetisation, digital ownership	Economic interactions, value systems	Virtual economies, digital asset ownership	Economic Systems

  provide a structured pathway from raw textual data to significant analytical categories. The eight core themes derived from this analysis were: interconnectivity, technological enablers, immersion, persistence, social engagement, multidimensional activities, representation of reality, and economic systems.

2.2.3. Definition Categorisation

To enhance analytical clarity and interpret the diversity of metaverse definitions, a secondary categorisation was applied to the 33 definitions identified in the systematic literature review. This categorisation was directly informed by the thematic analysis, which produced eight core themes representing recurring conceptual elements. Once these themes were established, each definition was re-evaluated based on its dominant thematic alignment.

The categorisation process used an inductive reasoning approach. Definitions were grouped into five conceptual categories based on the thematic domains to which they most closely related. For example, definitions that primarily emphasised the technological foundations of the metaverse, such as references to blockchain, artificial intelligence, or virtual/augmented reality, were grouped under “Technological Orientation”. Similarly, definitions that highlighted immersive spatiality or persistent digital environments were classified under “Spatial-Environmental Design”. While the eight themes reflect detailed conceptual patterns found in metaverse definitions, the five categorisation groups offer a higher-level synthesis, enabling comparative interpretation across dominant perspectives.

Table 3. Categorisation of metaverse definitions by conceptual focus and linked themes.

Category	Primary Focus	Representative Concepts	Linked Themes
Technological Orientation	Foundational systems and infrastructure	AI, VR/AR, blockchain	Technological Enablers, Interconnectivity
Spatial- Environmental Design	Virtual environments and spatial design	Immersion, digital twins, persistence	Immersion, Persistence, Representation of Reality
Social and Human Interaction	User presence and community engagement	Avatars, collaboration, presence	Social Engagement, Multidimensional Activities
Economic and Ownership Systems	Digital economies and virtual value systems	NFTs, monetisation, ownership	Economic Systems, Multidimensional Activities
Conceptual and Linguistic Constructs	Etymology, abstract definitions, theory	“Meta+verse”, conceptual synthesis	Representation of Reality, Interconnectivity

outlines the categorisation schema.

2.2.4. Architectural Model Categorisation

A thematic classification was applied to analyse the 25 metaverse architecture studies identified through the systematic literature review. These architectural models were organised into three high-level categories based on their design focus and conceptual framework:

• Technology-Based Architecture: These models are built upon the convergence of key technologies that facilitate metaverse capabilities, including blockchain, artificial intelligence, digital twins, 5G/6G networks, and edge computing. The classification is based on the pivotal role of enabling technologies in shaping architectural layers or components. Research in this area investigates how technological frameworks underpin interoperability, scalability, or decentralisation within metaverse environments.
• Domain-Based Architecture: These models are specifically designed for particular sectors, such as healthcare, education, or manufacturing. The classification criterion is the use of metaverse architecture to address domain-specific functional requirements. These architectures often feature customised components, such as the doctor/physician environment [57], smart manufacturing layer [65], or industrial application layer [66], and include considerations for ethical, regulatory, or contextual factors. They do not always follow a uniform structure but are tailored to meet the needs of their target domain.
• Layered-Based Architecture: These models utilise a structured, frequently multi-layered paradigm to articulate the essential components of the metaverse. Designed to encapsulate the extensive scope of metaverse systems within a universally applicable structure, they facilitate broad utility across disparate domains. They feature stack-based or modular designs that show how technologies, services, and user interfaces relate.

This categorisation was developed through inductive pattern recognition, examining recurring structural motifs, design intentions, and terminologies across studies. Thematic groupings were then created based on observable design logic. In contrast to the conceptual definitions, the architectural models were not evaluated against the eight previously established thematic themes. Instead, they were classified solely based on their structural and domain-specific focus.

3. Results

In the systematic review, it was found that 33 out of the 103 studies included offered clear definitions of the metaverse, while 25 suggested architectural models. These elements served as the foundation for the thematic analysis and categorisation detailed below.

3.1. Themed Identified from Thematic Analysis

Utilising a hybrid analytical approach that integrates word frequency analysis with a six-phase thematic process, eight overarching themes were discerned from the examination of 33 definitions of the metaverse. These themes encapsulate the recurrent conceptual elements prevalent in the literature.

The thematic analysis identified eight essential themes:

• Interconnectivity: The term fundamentally involves the seamless integration of virtual and physical realities, allowing users to engage across interrelated dimensions.
• Technological Enablers: The metaverse is an advancement of the conventional internet, with a more immersive and dynamic structure that utilises advanced technologies such as virtual reality, augmented reality, blockchain, and artificial intelligence.
• Immersion: The metaverse establishes immersive 3D settings that offer a profound sensation of presence and engagement. Facilitates interactive and instantaneous encounters via avatars and virtual environments.
• Persistence: The metaverse provides persistent and lasting virtual environments that coexist alongside the physical realm. Facilitates real-time collaboration and interaction, enhancing the metaverse’s enduring operability.
• Social Engagement: It serves as a social and interactive platform, facilitating user connection and collaboration. Facilitates instant communication using digital avatars, promoting community-oriented interactions.
• Multidimensional Activities: The metaverse enables a diverse range of activities, encompassing gaming, education, business, and content production. Offers a multitude of options for innovation and engagement across different industries.
• Representation of Reality: The metaverse effectively integrates avatars, realistic simulations, and digital twins to bridge virtual and physical realms. The simulation of real-world dynamics enhances user engagement and interaction. Avatars [67], serving as digital representations of individuals, constitute the primary means of presence and interaction within these environments.
• Economic Systems: The metaverse creates virtual economies facilitating the production, ownership, and exchange of digital assets. Several metaverse systems provide decentralised financial structures and markets for virtual products and services.

Fundamentally, these eight themes not only capture the descriptive repetition found across various studies but also highlight the conceptual evolution of the metaverse. This evolution is progressing toward a hybrid paradigm that seamlessly integrates spatial design, human experience, economic models, and technical enablers. The thematic structure provides a foundational lens for interpreting emerging frameworks in both academic and industrial discourse. Furthermore, these recurring themes have informed the classification of metaverse definitions into five conceptual categories, which enables a more structured and comparative understanding of how the metaverse is framed across different disciplinary and technological perspectives.

3.2. Thematic Categorisation of Metaverse Definition

The analysis of 33 metaverse definitions revealed recurring conceptual features through both word frequency and thematic analysis. The most frequently occurring terms—metaverse, virtual, world, immersive, internet, physical, avatars, users, digital, and universe—reflect a dominant narrative positioning the metaverse as a digitally immersive ecosystem that blends virtual and physical realities. The patterns were consolidated into five principal thematic areas for the classification of definitions.

Many definitions describe the metaverse as a convergence of these two domains [68,69,70], while others conceptualise it as a realm that transcends the physical world altogether [5,48,50,55,71]. It is often portrayed either as an extension of existing digital systems or as a distinct spatial layer beyond current internet frameworks. Across these interpretations, the Metaverse is frequently framed as the next generation of the internet [50,56], offering users a more immersive, interactive, and socially engaging way to experience digital content.

A key aspect of this immersive experience is the presence of three-dimensional virtual environments enabled by technologies such as augmented reality, virtual reality, mixed reality, and digital twins [57,72,73,74,75]. These spaces vary from realistic simulations of the physical world to imaginative, fantastical landscapes. Immersion is further supported through avatars, which serve as digital representations of users [69,75,76]. Avatars enable a sense of embodiment and personalised engagement, allowing users to navigate the Metaverse in ways that simulate physical presence. The metaverse is also widely defined as a communal environment, where avatars facilitate social interaction, collaboration, and the formation of persistent virtual communities [54,57,65]. These findings collectively illustrate an emerging consensus that defines the metaverse not merely as a technology stack, but as a socially immersive, persistent, and hybrid reality space that represents the evolving interface between humans, digital systems, and spatial computing.

While the eight themes reflect detailed conceptual patterns in metaverse definitions, the five categorisation groups offer a broader synthesis, enabling comparative interpretation across dominant perspectives. Based on this thematic grounding, the 33 definitions were grouped into five conceptual categories to better capture their dominant orientations: conceptual and linguistic constructs (6 definitions), spatial-environmental design (9 definitions), technological orientation (3 definitions), economic and governance systems (6 definitions), and social and human interaction (9 definitions). Each definition was allocated to its predominant theme based on the contextual emphasis. In cases where a definition encompassed multiple themes, the most salient conceptual focus was used to determine its categorisation.

• Conceptual and Linguistic Constructs (

  Table 4. Conceptual and linguistic constructs.

  Studies	Definition
  Ren et al. [65]	The metaverse, as a virtual universe that maps and interacts with the real world, is considered an ideal embodied version of the Internet for the future.
  Carrion [77]	The metaverse is conceptualised as a future iteration of the Internet, wherein virtual and real environments converge into a unified domain. The term “metaverse” is derived from the prefix “meta”, signifying “beyond”, and the suffix “verse”, denoting “universe”.
  Ritterbusch and Teichmann [21]	The term “Metaverse” is derived from the prefix “meta” (indicating transcendence), and the word “universe” refers to a theoretical synthetic environment connected to the physical realm.
  Lim et al. [78]	A frequent description of the metaverse is that it is an embodied form of the Internet.
  Nalbant et al. [79]	Metaverse is the combination of the prefix “meta” (implying transcending) with the word “universe”, describing a conceptual synthetic environment connected to the physical world.
  Dionisio et al. [80]	The term metaverse is a combination of the prefix “meta” (denoting “beyond”) and the suffix “verse” (abbreviation for “universe”). The metaverse denotes a completely immersive three-dimensional digital realm, as opposed to the broader notion of cyberspace, which encompasses the entirety of shared online space across all forms of representation.

  ): These definitions consider the etymology or figurative meaning of the term “metaverse”, frequently characterising it as an abstract or speculative idea, such as a realm “beyond the universe” or a new version of the internet.
• Spatial-Environmental Design (

  Table 5. Spatial-environmental design.

  Studies	Definition
  Ramolia et al. [68]	The metaverse represents the next phase of advancement of the internet, emphasising the development of an immersive experience within the virtual world.
  Almurtadha [81]	The metaverse indicates the future advancement of internet connectivity, establishing immersive digital environments where humans, locations, and items live virtually.
  Al-Emran and Deveci [75]	The metaverse is a tangible manifestation of the Internet, consisting of a cohesive amalgamation of interoperable, immersive, and communal virtual environments accessible by user avatars.
  Rawan and El Alami [82]	The metaverse is catalysing the next wave of innovation by creating new opportunities through the transformation of the digital realm (Internet) into a virtual realm, characterised by a unified, immersive, and persistent three-dimensional virtual space.
  Kusuma and Supangkat [83]	The metaverse is the next-generation Internet, defined by immersive three-dimensional virtual settings that replicate the physical world, allowing users to participate in diverse experiences through customisable digital avatars.
  Al-Ghaili et al. [56]	The metaverse is a concept that facilitates the creation of an environment where individuals can experience both real and virtual worlds.
  Braud et al. [84]	The metaverse is defined as a conglomeration of enduring virtual realms where users can exchange experiences at the convergence of the physical and digital domains.
  Kabanda et al. [73]	The metaverse is a virtual version of the Internet, conceived as a singular, universal, immersive environment facilitated by virtual reality (VR) and augmented reality (AR) headsets, often pictured in futuristic and science fiction contexts.
  Weinberger [54]	The metaverse is a network of immersive virtual worlds that intersect with reality, allowing users to interact, create, and consume content through avatars in a persistent, synchronous environment backed by a digital economy.

  ): Within this theme, definitions predominantly describe the metaverse as an environment that is digitally created or immersive. These definitions often emphasise the importance of 3D spaces, virtual environments, and the blending or simulation of physical and virtual worlds.
• Technological Orientation (

  Table 6. Technological orientation.

  Studies	Definition
  Wu and Hao [74]	The metaverse is a digital depiction of the physical world, encompassing networks, computing, the Internet of Things, blockchain technology, artificial intelligence, interactive elements, and video games.
  Karunarathna et al. [70]	The metaverse integrates digital reality and augmented physical reality into a distinct world, composed of numerous advanced features and facilitators.
  Mystakidis [50]	The metaverse constitutes a continuous, multi-user digital environment that integrates physical and virtual spaces. It is facilitated by virtual reality (VR) and augmented reality (AR) technologies, supports real-time interaction, and encompasses social, immersive platforms that have evolved from early avatar-based virtual worlds.

  ): These concepts draw attention to the enabling function of technologies like blockchain, extended reality, augmented reality, virtual reality, and artificial intelligence. The metaverse is presented as a byproduct of the advancement of technology.
• Economic and Governance Systems (

  Table 7. Economic and governance system.

  Studies	Definition
  Kontogianni and Anthopoulos [17]	The metaverse is a cohesive ecosystem of virtual realms that provides immersive experiences for users, transforming existing value and generating new value from economic, environmental, social, and cultural viewpoints.
  Alnuaimi and Alawida [71]	The metaverse is an interconnected network of immersive virtual worlds that overlap with and enhance physical reality, allowing users represented by avatars to interact, experience user-generated content, and participate in a persistent, synchronous environment with an integrated economic system incentivising contributions.
  Qayyum et al. [85]	The metaverse, derived from the prefix “meta” (indicating transcendence) and the suffix “verse” (abbreviation for universe), is a computer-generated realm characterised by a coherent value system and a self-sustaining economic framework connected to the physical world.
  Park and Kim [55]	The term “Metaverse” is a combination of the words “meta”, meaning transcendence, and “universe”, denoting a three-dimensional virtual realm where avatars participate in political, economic, social, and cultural activities.
  Wang et al. [5]	The metaverse, derived from the prefix “meta” (indicating transcendence) and the suffix “verse” (abbreviation for universe), is a computer-generated realm characterised by a coherent value system and a self-sustaining economic framework connected to the physical world.
  Cho et al. [14]	The metaverse defines an enhanced digital world that amalgamates physical and virtual environments via XR and artificial intelligence systems, enabling users to interact and trade virtual goods or services through cryptocurrencies, such as non-fungible token (NFTs), with each other and other virtual entities.

  ): The concepts in this category emphasise the metaverse’s economic operations and governance frameworks, such as decentralised or rule-based systems, digital ownership, persistent economies, and monetisation.
• Social and Human Interaction (

  Table 8. Social and human interaction.

  Studies	Definition
  Awadallah et al. [69]	The metaverse is the integration of the physical world with virtual surroundings, facilitating a new existence where user avatars can interact, engage in diverse activities, and conduct various transactions (financial, commercial, governmental, etc.).
  Aslam et al. [86]	The term “Metaverse” is derived from the prefix “meta”, meaning beyond, and the suffix “verse”, from “universe”. It represents the next-generation Internet paradigm, wherein users engage with software applications and other users as avatars within a three-dimensional (3D) virtual environment, with an emphasis on social connections.
  Ali et al. [87]	Metaverse is an evolving conductor of the future generation Internet architecture that generates an immersive and self-adapting virtual world in which humans engage in activities comparable to those in the real world, such as sports, employment, and socialising.
  Aydin [88]	The metaverse, a combination of “meta” (denoting transcendence) and “universe”, refers to a decentralised, three-dimensional online environment that is both persistent and immersive. In this space, users, represented by avatars, engage socially and economically with one another in a creative and collaborative manner, within virtual realms detached from the physical world.
  Yu et al. [76]	The metaverse is the notion of a completely immersive and global virtual environment for multi-user interaction, cooperation, and socialisation, representing the next generation of the Internet.
  Yang et al. [89]	The metaverse smoothly merges the physical and virtual realms, enabling avatars to engage in diverse activities such as creativity, exhibition, entertainment, social interaction, and commerce.
  Huang et al. [72]	The metaverse is broadly characterised as a vast online space where individuals engage through digital avatars.
  Setiawan et al. [90]	The metaverse is a virtual environment where people can create, explore, and interact without the necessity of physical proximity.
  Duan et al. [48]	The metaverse is a synthesis of “meta”, signifying beyond, and “verse”, derived from universe, representing the next-generation Internet where users, as avatars, engage with one another and software programs within a 3D virtual environment.

  ): Avatars and real-time participation are frequently used to highlight the metaverse as a social platform for human contact, teamwork, community development, and shared virtual experiences.

The presented classification, structured across five thematic dimensions, underscores the prevalent fragmentation in metaverse definitions, which range from those grounded in technological infrastructure to those oriented towards societal functions or abstract philosophical considerations. This inconsistency highlights the need for a clear definition of the metaverse.

3.3. Thematic Categorisation of Metaverse Architecture

A total of 25 distinct metaverse architectures have been proposed in the current literature. Through a comprehensive analysis of the literature, three primary categories of metaverse designs have been identified: 16 general architectures classified by layer count, 4 technology-based architectures, and 5 domain-specific architectures.

A total of 16 general-purpose metaverse architectural models, ranging from three to six layers, were identified and analysed.

Table 9. Layered-based general metaverse architecture.

	Study	Layer of Architecture
Three- Layer Architecture	Nkoro et al. [91]	Virtual World, Key Enablers Layer, Physical Layer
	Aloudat et al. [92]	Virtual Layer, Technical Layer, Physical Layer
	Ramolia et al. [68]	Virtual World, Intersection, Physical World
	Wang et al. [93]	Physical World, Virtual World, Enabling Technology
	Rawat and El Alami [82]	Ecosystem, Interactivity, Infrastructure
	Badeel et al. [94]	Virtual World, Intersection, Real World (Interface)
	Zhao et al. [95]	Virtual World, Interactive World, Physical World
	Chang et al. [96]	Physical World, Virtual World, Technical Layer
	Duan et al. [48]	Ecosystem, Interaction, Infrastructure
Four- Layer Architecture	Aslam et al. [86]	Physical Space, Social Space, Virtual Space, Metaverse Engine
	Truong et al. [97]	Virtual Life, Virtual World, Metaverse Tools, Metaverse Infrastructure
	Lim et al. [78]	Physical World, Virtual World, Metaverse Engine, Infrastructure
	Xu et al. [31]	Physical World, Virtual World, Metaverse Engine, Infrastructure
Five- Layer Architecture	Carrion [77]	The Physical World, The Infrastructure, The Metaverse Layer, The Technology Layer, The Democratic Layer
	Wang et al. [5]	Digital Life, Interconnected Virtual World, Metaverse Engine, Human Society, Infrastructure
Six- Layer Architecture	Ali et al. [87]	The Human World, The Physical World, The Digital World, Metaverse Engine, Intra-World Flow of Information, Inter-World Flow of Information

provides a comparative analysis of these layer-based general metaverse architectures. Analysis of nine studies utilising three-layer architectures reveals a consistent structural framework that organises the metaverse into three conceptual domains: a physical foundation, an interface for mediation, and a virtual experience layer. The base layer, often referred to as the physical world, real world, or infrastructure, consistently grounds the system in real-world data acquisition, sensing technologies, and network infrastructure, thus emphasising the fundamental role of computing and connectivity. The middle layer, while varying in terminology (e.g., technical layer, key enablers, interactivity, or intersection), serves as a technical mediator that facilitates data flow, system orchestration, and the deployment of immersive interfaces. The upper layer, typically labelled as the virtual world, virtual layer, or ecosystem, embodies the environment where user interaction, social engagement, and digital experiences occur. This triadic structure “physical-interactive-virtual” highlights a common architectural pattern that values system modularity and functional clarity, even though specific implementations may prioritise different disciplinary perspectives, ranging from infrastructure-centred to user-experience-focused models.

The analysis of four-, five-, and six-layer metaverse architectures reveals a clear trend toward increased structural granularity and conceptual sophistication. Four-layer models, such as those proposed by Aslam et al. [86], Lim et al. [78], and Xu et al. [31], commonly emphasise bridging the physical and virtual realms through a dedicated metaverse engine layer. These models often feature both physical world and virtual world components, supplemented by layers for social space or infrastructure, reflecting an emerging socio-technical integration that balances real-world context with immersive interaction.

In contrast, five-layer architectures, as introduced by Carrion [77] and Wang et al. [5], exhibit greater abstraction by incorporating higher-order layers like the democratic layer and human society, indicating a shift toward governance mechanisms and user-centric societal modelling. The five-layer models also reveal distributed responsibilities across technical, virtual, and socio-political domains, suggesting an evolution from system orchestration to platform accountability and interoperability.

Extending this progression, the six-layer model proposed by Ali et al. [57] introduces Intra-World and Inter-World Flow of Information layers, formalising cross-environment communication and systemic data exchange. This structure exemplifies a highly modular and scalable framework capable of supporting diverse, interconnected metaverse subsystems. Collectively, these findings highlight a developmental trajectory from simple immersion-focused architectures toward resilient, ethically aware, and interoperable metaverse infrastructures.

Technology-based metaverse architectures organise the metaverse around central enabling technologies such as artificial intelligence, blockchain, extended reality, 6G, and digital twins. The architectures highlight the computational infrastructure and networking capabilities necessary for metaverse deployment. For example, Jim et al. [98] and Wang et al. [6] emphasise the infrastructure and computational foundations necessary for metaverse deployment, including cloud-edge computing, data transmission, and immersive interfaces. Likewise, Aloqaily et al. [99] and Far and Rad [100] identify digital twins, blockchain, and IoT as fundamental technologies for metaverse implementation.

On the other hand, Dong et al. [101] designed an unmanned aerial vehicle (UAV) delivery solution for the virtual shopping environment. Although its application is e-commerce, it has been categorised as technology-based due to its structural emphasis on blockchain technology. This underscores the idea that design logic, instead of the specific domain, is the key factor in classification.

Table 10. Technology-based metaverse architecture.

Study	Layer of Architecture	Technology
Jim et al. [98]	AI, Big Data, Blockchain, 6G, Web 3.0, Extended reality, VR, AR, Gateway, Metaverse	Enabling Technologies
Dong et al. [101]	Access Layer, Application Layer, Blockchain Layer	Blockchain
Aloqaily et al. [99]	IoT Layer, Digital Twins Layer, Extended Reality Layer, Metaverse Manager, Blockchain	Digital Twins and 6G
Far and Rad [100]	Physical\Real World Layer, Link (User Interface) Layer, Metaverse (Digital World) Layer	Digital Twins

presents a comparative outline of the distinguishing features, underlying technologies, and structural emphases of these models, facilitating a clearer understanding of the influence of technology-driven considerations on architectural conceptualisations in contemporary literature.

The literature presents various metaverse architectures proposed for industrial applications, which are summarised in

Table 11. Domain-based metaverse architecture.

Study	Layer of Architecture	Technology
Zhang et al. [66]	Data Input Layer, Enabling Layer, Industrial Application Layer	Industrial
Ren et al. [103]	Physical Layer, Perception and Communication Layer, Digital Twins and Digital Native Model Layer, Industrial Data and AI Layer, Metaverse Engines Layer, Smart Manufacturing Layer, Human–Metaverse Interaction Layer, Smart Manufacturing Application Layer	Industrial
Ali et al. [57]	The Doctor/Physician Environment, The Metaverse/Virtual Environment, the Patient Environment	Healthcare
Bujari et.al [104]	Application Layer, Metaverse Engine, Virtual Layer, Operational Technology Layer, Physical Layer	Manufacturing
Wang et al. [102]	Ecosystem, Technology, Facility	Mobility

. For example, Wang et al. [102] developed a framework for metamobility architecture, which encompasses the capability to transport clients across both physical and digital environments, utilising connected and automated vehicles (CAVs) or other mobile entities such as urban air mobility (UAM). These vehicles function as physical conduits for customers to access and interact. Nonetheless, these models typically concentrate on highly specific and limited use cases.

The architectural categorisation demonstrates a shift from basic, immersion-centric designs to more intricate, modular architectures that integrate governance, scalability, and real-world elements. This evolution signifies the increasing conceptual sophistication of metaverse system design, with a growing focus on cross-domain interoperability, ethical implications, and strong infrastructural integrity.

These observations highlight significant conceptual trends and architectural developments that are influencing contemporary metaverse design discussions. Consequently, the themes and classification frameworks outlined herein represent substantive contributions aimed at resolving definitional uncertainties and architectural heterogeneity evident in the current literature.

4. Discussion

This section presents the core outcomes of this study and discusses their relevance to the stated research objectives. The presentation is structured around two key areas. First, it examines a conceptual definition of the metaverse derived from a thematic analysis of existing scholarly literature. The goal of this analysis is to clarify ambiguities and highlight the multidimensional nature of the concept. Second, it provides a comparative analysis of established metaverse architectures, focusing on their structural composition, conceptual logic and implementation relevance. In combination, these two approaches offer a cohesive synthesis that addresses both theoretical understanding and practical system design. By integrating qualitative synthesis with architectural analysis, the aim is to elucidate both the shared foundational elements and the conceptual distinctions that inform our understanding of the metaverse. These insights contribute to refining the definitional framework and highlight the strengths and limitations of current structural models in addressing the evolving technical, social, and governance needs within metaverse ecosystems, thus providing a basis for further discussion.

4.1. The Definition of Metaverse

The definitional diversity shown in the data indicates that the metaverse is a concept in active evolution, shaped by technical advancements and societal creativity. The findings predominantly highlight immersion, avatar embodiment, and communal interaction; however, a more profound analysis uncovers tensions between opposing conceptual frameworks, particularly concerning whether the metaverse constitutes an extension of existing digital systems or a completely separate reality paradigm. This disparity signifies an unresolved debate: some definitions regard the metaverse as the subsequent evolution of the internet [68,78], whilst others view it as a sociotechnical disruption that transforms the interplay between physical and digital realities [65,75].

Definitions of the metaverse often prioritise user experience, particularly spatial computing and social interaction via avatars. However, this emphasis sometimes neglects structural and governance considerations. For instance, few definitions explicitly address decentralisation, digital asset ownership, platform interoperability, or algorithmic governance, all of which are essential for the effective deployment of metaverse platforms. This omission reduces the utility of existing definitions for architectural design, regulatory frameworks, and ethical governance.

Given these gaps, this study proposes a definition that harmonises theoretical orientations with the practical imperatives of contemporary systems. Drawing upon eight core themes identified through thematic analysis (as outlined in Table 2), the metaverse is reconceptualised as a multifaceted domain that transcends a purely digital interface. This integrated perspective encompasses social systems, technological infrastructures, and immersive spatial experiences.

A proposed metaverse definition can be formulated by considering the results.

“The metaverse is a three-dimensional virtual environment that encompasses a vast universe of interconnected digital realms, enabled by advanced technologies, that exist parallel to the physical world, where users are represented by digital representatives, providing an immersive social, economic and interactive experience that transcends traditional internet applications by blurring the boundaries between real and virtual worlds."

This formulation swiftly addresses the deficiencies of prior definitions by explicitly incorporating socio-economic, experiential, and technological dimensions. It presents the metaverse as a technologically enabled ecosystem that facilitates a variety of interactions and value exchanges, rather than only as a visual or spatial environment. The definition is neutral concerning platform governance and ownership structures, rendering it applicable to both centralised and federated systems. Furthermore, it conforms to contemporary frameworks that emphasise scalability, modularity, and cross-platform compatibility as fundamental design concepts.

4.2. Metaverse Architecture

A total of 25 architectural models have been identified in the literature, categorised into three primary groups: general layered architectures, domain-focused architectures, and technology-based architectures. This study primarily focuses on the comprehensive analysis and comparative assessment of general layered architectures, while all three categories contribute to the architectural debate regarding the metaverse.

Layered metaverse architectures, comprising three to six layers, provide modular, abstract frameworks that enable the methodical conceptualisation and structural organisation of the metaverse across many areas. In contrast, domain-specific architectures are typically designed for specialised industries such as healthcare, education, or manufacturing, and hence, they lack the versatility needed for wider applications. Although technology-based architectures effectively highlight enabling infrastructures like artificial intelligence, blockchain, extended reality, 6G, and digital twins, they frequently lack a clearly defined layered structure that systematically organises system components. Thus, while these architectures elucidate the technological foundations of the metaverse, they fail to offer comprehensive architectural frameworks appropriate for cross-domain applications.

The classification of architectural models revealed instances where design intent and application domain were not perfectly aligned. One architecture [101], which targeted the e-commerce domain, was included under technology-based architecture because of its explicit emphasis on blockchain infrastructure. This highlights the analytical tension between functional deployment and conceptual orientation, necessitating interpretation based on authorial framing and structural design focus, rather than domain alone.

Moreover, both domain-specific and technology-oriented architectures frequently fail to satisfy critical needs such as modularity, scalability, interoperability, and data security, which are vital for extensive industrial use. Consequently, there is a considerable demand for versatile metaverse designs that can support sectoral diversity while ensuring a comprehensive and adaptive framework. This paper analyses how layered architectures conceptualise the metaverse and aims to discover recurring functional components, structural similarities, and their progression across different approaches.

The study analyses general-purpose metaverse architectures by concentrating on a set of well-established models that exhibit conceptual clarity, structural coherence, and widespread acceptance in the literature. These frameworks were selected for their impact on metaverse design discourse and their embodiment of fundamental, domain-agnostic architectural methodologies. The study facilitates a targeted comparison examination by focusing on a selection of exemplary models that provide modular layered frameworks. This method enables the recognition of repetitive structural patterns, thematic uniformities, and essential conceptual components that support the building of overarching metaverse systems.

4.2.1. Hierarchical Structure of the Metaverse Architectures

The study investigates general-purpose metaverse architectures employing models with layered, modular, and ordered frameworks. These designs help to enable the methodical conceptualisation of the metaverse and ease the comparison of fundamental structural elements. The analysis considered three sample models: the three-layer framework by Duan et al. [48], the five-layer architecture introduced by Wang et al. [5], and the four-layer structure jointly presented by Lim et al. [78] and Xu et al. [31]. The selection of these models was based on their established recognition within the academic literature as general-purpose metaverse architectures, their conceptual clarity, and structural integrity. Their recurrent presence in comparative studies and their fundamental impact on the development of metaverse design principles additionally substantiate their incorporation.

To ensure a systematic and meaningful comparison across these hierarchical frameworks, this analysis uses several comparison criteria. These criteria include (1) functional domain coverage, (2) granularity of layer differentiation, and (3) support for modularity, scalability, and interoperability. The three metaverse architectural models each employ a hierarchical structure to incrementally refine the division of system responsibilities, which enables conceptual clarity and architectural adaptability across diverse implementation scenarios.

Figure 3, Figure 4 and Figure 5 show representations of three-layer, four-layer and five-layer metaverse architecture, respectively, arranged from top to bottom layer. Each of these figures will be discussed separately.

A.

Three-Layer Architecture:

The three-layer architecture is the basic structure. Figure 3 illustrates that the three-layer metaverse architecture is structured into three principal components: infrastructure, interactivity, and ecosystem, emphasising essential functionality.

3.

Ecosystem Layer: It supports the seamless operation of the entire Metaverse, creating a parallel, dynamic, and interactive virtual world.

2.

Interactivity Layer: This layer serves as an interface between the virtual and real worlds, allowing the real world to be connected to the metaverse and the metaverse to be realised.

1.

Infrastructure Layer: The infrastructure layer contains the fundamental requirements for supporting the operation of a virtual world, including computation, communication, blockchain and storage. Blockchain is often incorporated at a fundamental level to guarantee decentralisation, transparency, and security within virtual environments. In this architecture, blockchain not only ensures distributed data integrity but also facilitates smart contracts and tokenised interactions that support higher-level functions, such as digital economies and decentralised governance. Although its structural role is within the infrastructure, its influence extends across layers, particularly within the ecosystem layer, highlighting the merging of technical and socio-economic design in metaverse systems.

B.

Four-Layer Architecture:

The four-layer metaverse architecture offers a disciplined framework that differentiates important elements engaged in the interaction between the real and virtual worlds. As illustrated in Figure 4, this architecture is composed of the following layers:

4.

Physical World: The physical layer includes key stakeholders, which are users, IoT and sensor networks, virtual services providers and physical space providers.

3.

Virtual World: The virtual world layer contains a virtual environment designed for education, trading, goods and services. Users are represented as digital avatars, allowing them to engage in activities that closely resemble those in the real world.

2.

Metaverse Engine: The metaverse engine orchestrates inputs from physical and virtual environments to create immersive experiences. Using AR / VR interfaces, haptic technologies, and the Tactile Internet, it is able to improve user interaction. Interoperability standards ensure consistency across platforms. Digital twin systems replicate physical assets in real-time, while AI manages functionalities like 3D rendering and avatar creation. Blockchain technologies support decentralised ownership and asset management. The engine also incorporates a virtual economy layer for transactions and content monetisation. These components collectively enable the creation of dynamic, responsive, and persistent digital environments.

1.

Infrastructure: The infrastructure layer is crucial for enabling efficient access by distributing computing resources closer to end-users, which significantly enhances user experiences through low latency and high-speed data transfer. It is designed to support high-density networks capable of managing the ever-increasing data demands of modern applications. By employing advanced communication technologies, this layer enhances bandwidth and overall efficiency, while a multi-layered computing approach balances performance with scalability. Basic tasks can be processed directly on user devices, allowing complex tasks to be offloaded to distributed servers, effectively optimising resource usage. Furthermore, AI-driven optimisation techniques are applied to improve efficiency and reduce network load. Security is paramount, ensuring the management and verification of digital assets while also supporting peer-to-peer transactions and interoperability across various virtual environments. This infrastructure layer facilitates cross-platform accessibility and resource-sharing, creating a cohesive and efficient distributed ecosystem.

C.

Five-Layer Architecture:

The five-layer metaverse architecture is a detailed and flexible framework intended to include the entire range of virtual environment creation and engagement. Figure 5 illustrates that this architecture comprises the following layers.

5.

Digital Life: The digital life layer represents the diverse virtual experiences, services, and economies within the metaverse. It encompasses multiple interconnected sub-metaverses, each offering unique digital environments, applications, and services that cater to various user needs, such as gaming, social networking, education, virtual commerce, and digital entertainment.

4.

Interconnected Virtual Worlds: The interconnected virtual worlds are an expansive digital landscape that comprises multiple interconnected distributed virtual worlds, often referred to as sub-metaverses. Each of these sub-metaverses caters to specific interests by providing a range of virtual goods and services, including gaming, social networking, online museums, and virtual concerts. Users can explore diverse environments within these sub-metaverses, immersing themselves in unique game scenes or navigating vibrant virtual cities. Central to the experience are avatars, which act as digital representations of human users, allowing them to engage and interact within these virtual realms.

3.

Metaverse Engine: The metaverse engine merges physical, digital, and virtual elements into a cohesive experience, leveraging big data to generate and continuously update expansive virtual worlds. With the capability for real-time rendering, users can seamlessly interact between their physical surroundings and the digital landscape. This immersive environment is supported by technologies such as extended reality, human–computer interaction (HCI), and brain–computer interfaces (BCI), allowing individuals to control avatars through their senses and physical movements. This multifaceted platform not only facilitates gaming and social interactions but also enables virtual commerce. AI analytics play a crucial role by enhancing user experiences, optimising system performance, and sustaining large-scale simulations. The environment ensures high-definition rendering and creates realistic virtual settings, while also supporting decentralised trade of virtual goods and services through transparent, trust-free transactions. Additionally, user-generated content and diverse avatar activities contribute to a spontaneous and thriving virtual economy.

2.

The Physical Infrastructure: This layer is crucial as it enables seamless interactions between the digital and human worlds by providing essential support for data perception, transmission, processing, and caching. It includes components like smart objects, sensors, and actuators, which facilitate physical control for these interactions. Additionally, this layer supports networking capabilities through both wired and wireless systems and offers the computing power and storage necessary for various metaverse applications. Its ability to ensure real-time, high-performance processing is vital for the smooth operation of the metaverse.

1.

Human Society: The human society layer of the metaverse emphasises the centrality of users, their psychological makeup, and their social interactions. This layer is designed to create intuitive and immersive experiences that cater to the behaviours and needs of individuals. By leveraging technologies such as VR and AR helmets, smart glasses, and a range of wearable devices, the metaverse offers seamless interactions within its digital realms. Users can control their digital avatars, allowing them to participate in diverse activities that foster connection and engagement. The layer promotes intuitive communication between humans and the virtual environment, effectively blending virtual, augmented, and mixed reality to provide rich and immersive experiences that reflect the complexities of human society.

4.2.2. Conceptual Similarities Across Metaverse Architectures

This section examines the conceptual similarities among three-layer, four-layer, and five-layer metaverse architectures. The accompanying figures visually illustrate how these frameworks, despite differences in structural detail and terminology, frequently converge on functionally equivalent components. Each comparison underscores shared core functionalities, including user interaction, computational processing, and infrastructure support.

Figure 6, Figure 7 and Figure 8 illustrate the metaverse architecture, representing three distinct architectural models: the three-layer, four-layer, and five-layer architectures, along with their interrelations. The illustration aims to highlight the hierarchical structure of various architectures and the conceptual commonalities between levels that perform analogous duties but are designated differently among architectures. Bidirectional arrows point to areas of conceptual overlap or functional equivalency by indicating layers that carry similar purposes in the comparative structures.

The three-layer and four-layer architectures, as shown in Figure 6, exhibit significant structural similarities. Both frameworks establish a fundamental infrastructure layer responsible for processing, communication, storage, and the integration of enabling technologies. Each architecture utilises blockchain to facilitate secure digital ownership, economic transactions, and trust management inside the virtual ecosystem.

A specific layer in both models enables interaction between the physical and virtual realms, referred to as “Interactivity” in the three-layer architecture and manifested through the metaverse engine and virtual world in the four-layer architecture. Moreover, both architectures prioritise immersive user experiences by utilising technologies such as virtual reality, augmented reality, and spatial computing, and depend on digital representations to facilitate avatar-based or system-level interactions.

Ultimately, each framework facilitates a virtual environment or ecosystem layer that fosters social, cultural, and economic activities, supporting enduring and multi-user digital communities. These common traits demonstrate a fundamental congruence in design principles, emphasising interoperability, scalability, and user-centric engagement across platforms.

A comparative analysis of the three-layer and five-layer architecture, as shown in Figure 7, highlights several patterns of conceptual equivalence. Both architectures include an infrastructure layer that serves as the technical foundation of the metaverse, providing essential computing and networking resources. In both architectures, blockchain technology, at a fundamental level, provides secure digital ownership, trustless transactions, and the development of decentralised virtual economies.

The three-layer approach incorporates blockchain in the infrastructure layer to enable smart contracts and distributed governance, whereas the five-layer architecture integrates it into the metaverse engine to enhance asset management and ensure transparent economic exchange. In the three-layer architecture, the ecosystem layer consolidates functions related to user engagement, application services, and social interaction.

In contrast, the five-layer architecture adopts a more distributed approach, separating these functions across three distinct layers: the digital life layer, the interconnected virtual worlds layer, and the metaverse engine layer. Together, these layers manage immersive environments, real-time interactivity, and content rendering. Additionally, the five-layer architecture explicitly includes a human society layer, which emphasises user-centric aspects that are present, but not formally defined, in the three-layer architecture.

Similarly, the four-layer and five-layer architectures exhibit closely related functional characteristics in Figure 8. The alignment of infrastructure components is once again evident. The metaverse engine layer in the four-layer architecture corresponds directly to the metaverse engine in the five-layer framework. Additionally, the concept of the virtual life layer in the four-layer architecture overlaps with the digital life and interconnected virtual worlds in the five-layer architecture.

The five-layer architecture’s enhanced differentiation of social dynamics and digital presence, through the human society layer, signifies an advancement in structural clarity and societal modelling. Moreover, blockchain technology is featured in both frameworks to support secure asset ownership, decentralised trade, and digital economy management.

Across all three architectural frameworks, recurring functional domains are evident, particularly in the areas of infrastructure support, immersive systems, and user interaction layers. Despite variations in terminology and layer divisions, these models converge in addressing the fundamental requirements of metaverse design, such as real-time processing, virtual environment management, and social engagement. These conceptual similarities demonstrate a developmental continuity from simpler to more specialised structures, underscoring that evolving architectures, while diverse in structure, remain anchored in a set of shared foundational principles.

4.2.3. Merits and Shortcomings of the Different Models

Although the architectures share foundational elements, they exhibit significant divergence in their approaches to managing user interaction and experience. The three-layer architecture integrates interactivity, user environments, and economic activity within broad, consolidated layers, specifically, the interactivity layer and the ecosystem layer. In contrast, the four-layer architecture refines this structure by segregating these functions into more specialised components. For example, the interactivity layer is divided into a physical world layer, which manages real-world user inputs and sensor data, and a metaverse engine layer, which addresses immersive technologies, AI, and data synchronisation. This enhanced granularity supports modularity and scalability, facilitating more flexible system design and a clearer delineation of responsibilities. While the simplicity of the three-layer architecture may be advantageous in small-scale or closed environments, the expanded structure of the four-layer architecture offers greater adaptability in more complex use cases [105].

The four-layer architecture offers enhanced structural clarity and functional specialisation relative to the three-layer architecture; yet, both frameworks demonstrate considerable limits when utilised in extensive, socially integrated metaverse settings. A significant limitation is the lack of structural support for interoperability. Both the three-layer and four-layer architectures lack a defined architectural mechanism to enable cross-platform interaction. Rather, these models typically presume isolated or self-sufficient ecosystems. This design methodology restricts users’ capacity to transfer assets, identities, or social connections between platforms, leading to disjointed experiences that impede the overarching goal of a cohesive metaverse [106]. This constraint highlights the essential requirement for architectural improvements that emphasise interoperability as a primary design element [107].

The five-layer approach mitigates several of these constraints through its more detailed and modular framework. By incorporating distinct layers, including the human society layer and the interconnected virtual worlds layer, it provides improved support for social complexity and cross-platform functioning. The interconnected virtual worlds layer explicitly promotes interoperability by allowing seamless transitions and data interchange among scattered sub-metaverses. This structural inclusion differs from the three-layer and four-layer, which presume isolated ecosystems and lack methods for identity transfer, asset continuity, or cross-platform connections. The separation of once-integrated functions into distinct, purpose-driven layers enhances modularity, scalability, and system clarity.

A significant shortcoming in the three-, four-, and five-layer metaverse architectures is the lack of a dedicated governance layer. Although all three frameworks incorporate blockchain technology, primarily to support decentralised data integrity, digital ownership, and secure transactions, this integration serves as a technological enabler rather than a formal governance mechanism. Blockchain facilitates elements such as smart contracts and peer-to-peer exchanges, but it does not architecturally model processes like regulatory compliance, content moderation, or ethical oversight.

As metaverse platforms continue to expand in both scope and societal influence, the absence of integrated governance mechanisms has emerged as a significant vulnerability [108]. Regulatory compliance, content moderation, and user rights management are often perceived as external or secondary concerns, resulting in a structural governance gap [109]. The assumption that legal and ethical oversight can be managed externally to the system design is increasingly untenable, given the rising expectations for platform accountability and responsible data stewardship [77,110].

Among these three architectures, the five-layer architecture most effectively addresses governance by incorporating a human society layer, which integrates elements of user behaviour and social presence [5,111]. Nevertheless, this layer predominantly emphasises psychological and experiential aspects, without formally modelling legal, regulatory, or ethical governance structures. Consequently, even the most advanced framework lacks a comprehensive governance framework [31].

Furthermore, the disaggregation of previously unified functions into distinct, purpose-specific layers within the five-layer architecture enhances modularity, scalability, and systemic transparency. While the three-layer architecture may remain appropriate in controlled or experimental settings due to its simplicity, its structural limitations impede its applicability in large-scale or ethically complex environments. Conversely, the five-layer architecture signifies not only a technical advancement but also a conceptual shift towards metaverse systems that are resilient, interoperable, and ethically aligned.

The evolution of the metaverse underscores a vital understanding: for platforms to be sustainable, they must incorporate not only governance structures but also explicitly integrate user-focused design and systemic interoperability into their foundational framework. As the metaverse becomes more intertwined with social, economic, and regulatory spheres, maintaining these platforms demands both technological advancements and institutional responsibility. Future metaverse frameworks need to go beyond simple interaction and immersion by embedding governance, privacy, data management, and ethical principles into their core design, thereby fostering robust, inclusive, and scalable digital ecosystems.

Table 12. Key observation for metaverse architectures.

Key Observations	Explanation
Infrastructural Consistency Across Models	All architectures incorporate a foundational infrastructure stratum that furnishes computing, networking, and storage resources, reflecting shared architectural suppositions regarding technical necessities.
Architectural Insight	Architectural design strategies vary, encompassing the consolidation of diverse functionalities within singular layers as well as the distribution of responsibilities across specialised, modular components, with the aim of fostering clarity and modularity.
Architectural Absence of Governance Mechanisms	None of the architectures includes a dedicated governance layer. Governance is assumed or partially supported through technologies like blockchain.
Interoperability Support	Only the five-layer architecture explicitly incorporates an interconnected virtual worlds layer to facilitate cross-platform interactions. Others assume isolated environments.
Progressive Structural Refinement Across Models	The shift from a three-layer to a five-layer architecture highlights a noticeable move towards increased structural detail, modularity, and system capabilities, reflecting a heightened preparedness for sophisticated metaverse applications.
Mismatch Between Structural Potential and Implementation	Architectural components conceptually support functions like governance, but practical implementation often fails to embed them meaningfully.

presents key insights across the three-layer, four-layer, and five-layer metaverse architectures. These observations highlight recurring structural patterns, functional priorities, and design limitations that have emerged from the evolution of architectural models.

4.3. Societal and Ethical Implications

While this study primarily focuses on conceptual clarity and architectural coherence, it is equally important to address the broader societal and ethical considerations that arise from metaverse frameworks. Key areas of concern include, but are not limited to, privacy and data ownership, equitable access, and the socio-psychological consequences stemming from highly immersive environments.

Metaverse systems frequently require the collection of comprehensive user data that includes biological, behavioural, and emotional information [112]. This raises substantial concerns about user consent, data exploitation, and prolonged surveillance [113]. The reviewed architectures, especially those lacking specialised governance layers, provide insufficient structural support for safeguarding data or overseeing the ethical use of user information. In the absence of integrated privacy-preserving safeguards, such systems jeopardise transparent data practices and compromise user autonomy [57]. While existing legal frameworks, like the GDPR, are applicable to metaverse environments, there is currently no specific, harmonised international regulation designed to address the unique challenges it presents [114,115].

Access to metaverse technology is often limited by economic costs, digital literacy, and physical or cognitive obstacles [114]. None of the three examined models clearly incorporates accessibility or inclusivity as fundamental design principles. The lack of such measures can result in the exclusion of disadvantaged people and exacerbate existing digital disparities. A metaverse aligned with ethical standards must incorporate universal design principles to guarantee equal involvement among varied user populations.

The highly immersive nature of metaverse environments has the potential to reshape individual perceptions of identity, community, and reality. Sustained engagement within these digital spaces can have ramifications for mental health, social dynamics, and the expression of cultural values [116]. While the five-layer architecture includes a human society layer that touches on these issues, its capacity to incorporate ethical protections or strategies for safeguarding psychological well-being and cultural diversity remains limited.

Existing metaverse architectures predominantly adopt a technology-focused approach, often neglecting societal resilience and ethical design considerations. Future architectural models should therefore evolve to integrate governance mechanisms, inclusivity principles, and psychosocial safeguards as core tenets. Embedding these elements at a structural level is essential for the development of scalable, accountable, and ethically sustainable metaverse ecosystems.

5. Conclusions

This study employed a mixed-methods qualitative design combining a systematic literature review (SLR), word frequency analysis, and thematic analysis to examine the evolving conceptualisation and architectural foundations of the metaverse. Drawing from 103 academic sources, it identified and analysed 33 definitions of the metaverse and 25 general-purpose architectural models. Through word frequency and thematic analysis, the study synthesised a refined definition of the metaverse, emphasising immersion, persistence, interconnectivity, and economic systems. Notably, the study also categorised definitions into recurring conceptual themes, providing a structured understanding of how the metaverse is defined across disciplines.

A significant contribution of this study is the categorisation and comparative evaluation of foundational architectural models, specifically the extensively referenced three-, four-, and five-layer frameworks. The selection of these models was guided by their general-purpose applicability, conceptual transparency, and structural integrity. This allowed for a concentrated comparison of fundamental architectural components, such as infrastructure, interactivity, immersion, and socio-economic layers, alongside their potential for expansion and compatibility across metaverse environments.

The analysis identifies common assumptions regarding core infrastructure and interaction layers, while also highlighting variations in modularity, scalability, and interoperability. The five-layer architecture represents a conceptual advancement that incorporates dedicated layers for societal engagement and cross-platform interaction. Nevertheless, all three architectures display a gap between architectural potential and practical implementation, particularly in areas such as the integration of formal governance and ethical system design. These limitations are acknowledged but fall outside the analytical scope of this study, which concentrates specifically on definition and architectural structuring rather than governance policy or ethical enforcement.

This research establishes a solid conceptual base for future studies by defining clear boundaries and architectural frameworks. Future investigations should examine how architectural models can incorporate formal mechanisms for governance, data privacy, legal compliance, and ethical responsibility, possibly through modular governance layers or integrated regulatory logic. Such integration is essential for the metaverse to develop into a scalable, inclusive, and reliable digital ecosystem.