In computer lingo what is a MUD?

A MUD, or Multi-User Dungeon, is a text-based online game that combines elements of role-playing games, interactive fiction, and multiplayer online gaming. Players navigate through a virtual world, interact with each other and non-player characters, and engage in quests or battles, all through text commands. MUDs were foundational in the development of modern MMORPGs (Massively Multiplayer Online Role-Playing Games) and often feature complex social interactions and gameplay mechanics.