Re: Forum is Category – bbPress 1.0 alpha
My take on it (completely uninformed BTW) was that a category acts like a parent that won’t have any topics in it. There have been requests in the past when creating multiple subforums to be able to skip putting topics in a parent forum (now called a category). It would just be a container for subforums.
https://trac.bbpress.org/ticket/520
https://bbpress.org/forums/topic/plugin-request-forum-categories