Topics/threads are created by users within a board and often include an initial post followed by a series of replies to that post.

The Threaded view is a specific way to view a topic/thread that displays the relationship between messages. This is different from the Msg List view, which displays messages in the order they were posted.

A topic/thread can be read as Simple, Summary, or Expanded in both the Threaded and Msg List formats.

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