A Review of Metaverse's Definitions, Architecture, Applications, Challenges, Issues, Solutions, and Future Trends

Metaverse is a vision enabling to constitute an environment in which someone could see real and virtualized worlds. The Metaverse is a product (or something similar as we do not yet know its final form) of such technologies. In this circumstance, when applications that utilize the Metaverse are used, there seem to be no transportation charges, and there is no cap on amounts of individuals, users, players, learners, or trainee who can take part. Hence, and due to such a feature, the Metaverse has attracted various researchers from different fields where it has been exploited by them to contribute to those fields and research areas. As for example, it is possible to teach various target audiences by offering different events and classes from any location in the globe. In order for a participant to utilize the Metaverse, there are necessary conditions to be considered as well as other settings to be initialized. In line of this, virtual reality, augmented reality, availability of required sensors, smart glasses, headsets, and few others are considered some examples of such conditions and settings that the Metaverse requires. Despite the advantages that Metaverse offers us, there are a number of considerations that must be taken into account while developing it by interested researchers. One of these concerns is the Metaverse privacy regarding the participants (represented as avatars inside the Metaverse environment). Another issue is that since the Metaverse is still in its early stages, many attempts have to be made from interested researchers who engage to develop it to enhancing it. This review aims to survey related articles that concern the Metaverse and its development providing a review of the chronological stages throughout the history of the development of Metaverse. It aims also to list a number of recent technological advances allowing the Metaverse. Besides, Metaverse's definitions, properties, architecture, and applications have been discussed and listed in this review. The novelty of this article is that it has suggested a framework to a number of issues that are still paid attention for potential solutions by researchers aiming to contribute to researchers and designers to consider such an issue and its corresponding solution for future research works and enhancement. Challenges faced by researchers and other relevant concerned issues related to Metaverse have been in detail discussed and highlighted. Besides, future trends have been clarified.