Yahoo! Message Boards includes a set of categories, boards, and topics/threads to organise the thousands of discussions going on each day.

Categories are an organisational structure created by Yahoo!. You can browse through the Message Boards directory to find boards that live inside specific categories. Some categories contain only one board and some contains hundreds.

Boards are also created by Yahoo! and live within categories. They contain the individual threads in which you post your messages.

Topics/threads are discussions started by users related to the subject of the board in which they are created. You can share your opinions and thoughts in an existing thread, or you can start new thread if your issue isn't already being discussed.

For more information on threads, see "What does threaded mean?"