Your "home page" shows a stream of posts fed by many message boards. Now you can choose what you want to appear in that home stream. Edit your profile and select your "home stream".
The choices are:
The default option is "All User Posts" (which is how it's always been). If you are not logged in, you see "All".
Streams can be customized even further by hiding boards or users you don't want to see. When you "hide" a board or a user, those posts will not appear in your stream.
The different streams are in the Streams section in the upper right, so you can view them anytime. For example, if you want to check out the latest gaming news, click the gaming stream.
Hopefully the concept of "streams" of topics is easy to understand. Let me know what you think.