Player versus monster or PvM is the conventional type of MUD as opposed to Player versus player, often used to make this distinction. In computer gaming, a MUD (multi-user dungeon, dimension, or sometimes domain) is a multi-player computer role-playing game typically running on a bulletin board system or Internet server. ... Player versus player, or PvP, is a type of combat in MMORPGs, MUDs and other computer role-playing games pitting a players skill against anothers, where the goal is ultimately the death of the opponents player character. ...
Playerversus environment, (or PvE, sometimes playerversusmonster, or PvM), is a gameplay distinction, in contrast with playerversusplayer (short: PvP) gameplay.
Playerversus Environment is a type of gameplay common to RPGs in general.
In addition, PvE players can "grow" their characters, gain experience, learn skills, acquire better weapons and armor, improve titles etc. This is done mainly by completing quests and missions, venturing into explorable areas to fight monsters, and farming.