# Metaverse Architectures: A Comprehensive Systematic Review of Definitions and Frameworks
## 3 Results
### 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 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 in \begin{table}
\begin{tabular}{p{142.3 pt} p{284.5 pt}} \hline \hline
**Studies** & **Definition** \\ \hline [PERSON] 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.). \\ \hline [PERSON] 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. \\ \hline [PERSON] 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. \\ \hline [PERSON] [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. \\ \hline [PERSON] 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. \\ \hline [PERSON] 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. \\ \hline [PERSON] et al. [72] & The metaverse is broadly characterised as a vast online space where individuals engage through digital avatars. \\ \hline [PERSON] et al. [90] & The metaverse is a virtual environment where people can create, explore, and interact without the necessity of physical proximity. \\ \hline [PERSON] 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. \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Social and human interaction. frastructure, 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.