A room is a discrete location within an adventure, normally connected to one or more other rooms via exits. Adventurers and monsters normally occupy a room, and most adventures require the player to move his character from room to room to collect artifacts, encounter monsters, and solve puzzles.
Rooms frequently represent room-like spaces such as chambers, halls, corridors, etc., but this isn't required. Some adventures have rooms that represent smaller spaces, like discrete areas within a single large chamber; setting up rooms to represent points along a single long corridor is a common example. Other adventures use rooms to represent larger areas like streets, buildings, regions, or entire countries. Some imaginative adventures even have rooms that represent the anatomy of the body.
Authors occasionally allow adventurers to move beyond the confines of discrete rooms: Donald Brown's The Lost Island of Apple gives the player the ability to move his character freely across a graphical map of an island in order to travel from one set of rooms to another, and Pat Hurst's Buccaneer! allows the adventurer to travel over a sea in a sailing ship.