Metaverse is a compound word of meta and the universe, which signifies “virtuality” and “transcendence”, and is a more evolved term than VR. Alternatively, the metaverse is defined as an independent service provided for various social phenomena that appear in the market environment as technology develops [
6]. The metaverse emerged in the early 2000s as a part of the gaming industry, providing independent communication services among users. However, with the invention of smartphones and social networking services that highlight convenience and accessibility, users have flocked to social media, and the number of users in the metaverse has gradually declined [
7,
8]. However, the market environment has abruptly changed since the outbreak of COVID-19, and the metaverse has returned in full swing as the digital platform that connects consumers, and producers have converged with 5G networks and sophisticated devices. Specifically, the metaverse can be considered a technology optimized for the market environment created by the commercialization of 5G, boasting ultra-fast, ultra-connected, and ultra-low latency services, boosted by the COVID-19 pandemic in early 2020. With the commercialization of 5G, technologies that can implement VR, AR, and mixed reality (MR) have emerged, and the metaverse is drawing more attention as a platform for contactless environments.
In its nascent stage, the term metaverse was used interchangeably with VR, but its use expanded in diverse ways. For example, the
Second Life game, released in 2003, was created to generate profits through social exchanges and the economic activities of multiple users in a virtual space based on 3D graphics. Based on this, a VR version of
Sansar was released [
9]. In Niel Stephenson’s 1992 novel
Snow Crash, the scope of the metaverse, a space where everyday life and economic activities were made possible through avatars, was further expanded [
10]. Travis Scott, an American hip-hop artist, presented a metaverse performance on the Fortnite platform in 2020, with more than 12 million viewers watching the performance in real-time. It is estimated that the revenue from a single metaverse performance would be at least USD 1 million, with an estimated total of USD 20 million [
11]. Kwok and Koh [
12] argued that, as reality and virtuality interact and evolve within a space, they transform into a world that creates value through social, cultural, and economic activities. Thus, the current metaverse is defined as an extended virtual world in which emphasis is placed on artificial reality and AR [
13]. Bolger [
14] divided the metaverse into four types according to the space and nature of the information implemented on the platform. The first is “lifelogging”, which automatically records, stores, and shares information that individuals experience and feel in their daily lives in the digital world through social media services, such as Facebook, Instagram, and Twitter. The second is “AR”, which summons 3D objects in reality to provide realistic digital information, such as
Pokemon Go and
Snow. The third is “mirror world”, in which Google Earth and Kakao Maps render a digital implementation of the real world to the virtual world and link it back to the real world. The fourth is “VR”, which implies experiencing a new virtual world that does not exist as an individual-centered virtual world in spaces, such as Zepeto and Roblox [
9]. The current status of the metaverse is that there are countless key technologies for implementing them. It is diverse, spanning the basic technologies of 3D, blockchain, AI, 5G, MR, AR, and VR to the applied technologies of avatar and cryptocurrency [
15].