On the "Manage Forums" tab, you can "+ Add new forum", this would create a new category/room that could be use to filter the content.
When the user enters to your community on the "FORUMS" tab, they will find tags and categories, and it is possible to filter by both.
If you want to add tags to latterly classify your content, you can add them from two places:
- Go to "Tags" tab and "Create a new tag". Then you can use them when creating content.
- When editing a "new message" in the "FORUMS" tab, or when creating a new "Post" in "BLOG", when clicking in "Add tags" you can select from the existing ones or add a new one.