Conferencing is like a large room full of bulletin boards. Each bulletin board is devoted to a general area of interest. People can visit the world news bulletin board or the sports bulletin board or the "let's be silly" bulletin board, for example.
Each conference (or "bulletin board") has subsets of the overall area of interest. Each subset is called a topic. The sports conference might have topics on baseball, basketball, football and bicycling.
Any person can type a comment and "post" it to a specific topic using a simple set of keystrokes to place it there. It will stay there indefinitely. Comments are stored and read sequentially in the order they are posted. The next person who comes by can read what has been posted, type a response and post that. Another person comes by and adds to the electronic conversation.
Conferences are much like conversations except they do not happen in real time. Bob can log on, drop by the sports conference and type his message in the football topic: "How about that Joe Montana? He's over the hill, isn't he?"
Jane can come by an hour later, or a day later, see Bob's comment and respond to it, "Are you nuts? Joe's never been in better form!"
The next person who comes by reads *both* comments, one after the other. To that person, the conversation is as good as "real time" because the comments flow just like a real-time one.
The advantage to conferencing over real-time conversation or "chat lines" is that it frees your creativity. You have a chance to compose your thoughts. You cannot be interrupted. You can be as brief or lengthy as you wish. You can get up from your computer in the middle of typing your comment, make a cup of coffee, come back and continue with what you were saying. Nobody will be waiting, tapping his fingers and getting annoyed.