If you are not logged in, the 'Active Topics' link in the Header, will show a list of all topics that have been created or updated since your last visit.
If you are logged in, the 'Active Topics' link will change to 'My Topics', which gives you a listing of all topics that have been created or updated since your last visit.
The administrator can also set up the forums so that each thread you read is marked in the database. If this option is set, then new topic (or topics with new posts) will not be marked as read until you have actually read them.
There will be also an Second Tab 'Favorite Topics' which shows all Topics which you have tagged as Favorite Topic.