Quote: "Map, Level, World. what's the difference? World building programs such as 3DWS and CS4 are often described as either a map editor, level editor or a world editor. What is the difference?"
its all relative to each computer game or program.
a map can be a level and a world.
a world can be a map and a level.
a level can be a map and a world.
your level however might consist of a map and extra data.
your world might consist of a series of maps or just one, that is a level with other data.
your map might be a level with data.