Online games and virtual worlds are not the same thing. If you’re building an MMO, you better be sure which one you intend to make.
Online game: a game played using network connectivity.
Virtual world: a simulation of space. cf long usage in the VR community, 3d viz community, etc. Somewhat deprecated since these days, everyone wants connectivity.
Online virtual world: a simulation of persistent space connected to via a network, wherein users are represented by proxies often terms avatars. Note thatboth “online” and “virtual” are often elided from the term.
Synthetic world: see online virtual world.
MUD: old term for online virtual world.
Avatar: the proxy by which a user is represented in an online virtual world.
Toon: see avatar.
MMOG: an online virtual world wherein embedded systems layered atop the spatial simulation present game rules.
MMORPG: an MMOG where the game presented is an RPG.
“Worldy”: an adjective applied to MMORPGs to describe RPGs with certain rather specific game characteristics, such as freedom of character construction, diverse rule systems including non-combat roles, etc.
“Social”: an adective applied to online virtual worlds to indicate that their primary emphasis is not on games.
Metaverse: the hypothetical idea that online virtual worlds would be linked together to form a single network.
Mirror world: an online virtual world that mirrors data from the real world.