What do the terms room, exit and building mean in this context?

It might help to think of the MOO in spatial terms, as a place that you can move through, just as ancient Rome was.

A “room” on VRoma (or any MOO) is a discrete area within which anyone who is logged into VRoma and in that room can communicate with anyone else also in that room. A virtual “room” on a MOO may represent an actual room, a whole building, or even a huge area like the Circus Maximus. The defining factor is communication: everyone in a room can communicate with everyone else in that room, but those in other rooms will not be party to the conversation. If you are creating a large structure (e.g. the arena of the Colosseum), this might in fact be comprised of several “rooms”, especially if you want to add lots of details. Rooms are connected by named “exits”, which one must pass through in order to reach other rooms. Exits can be named after compass directions (north, south, east, west, northwest, southeast, etc.) or after the actual structure one passes through or along to get to the next “room” (e.g. door, curtain, path).

When designing a building or other area, you decide how it will be divided up into rooms and exits, and what these will be called. This decision will be based on:

• how the building or area was actually navigated in antiquity — is there some natural division into sections?
• how complex the entire building or area will be. As a rule, you should try to limit your descriptions of a room to 10-12 lines of text or less (though this does not preclude adding objects with further descriptions to your room)

A “building” (noun) is a set of rooms and exits that comprise a discrete area on the MOO, either an actual building (e.g. the Colosseum) or other kind of area (e.g. a forum).

“Building” (verb) on the MOO refers to the process of designing your building or area then entering a command that creates new rooms and exits and allows you to enter your descriptions of these rooms. It also includes the addition of details, images, and links to web pages.