The other included taxonomy in WordPress is tags. Posts can belong to multiple categories, and they must have at least one category set. Posts published without a category selected are automatically added to the “Uncategorized” category by WordPress. When a post is included in a category, it is displayed on the archive page for that category. The categories that a post belongs to are usually displayed on the post as well. If and how they are displayed vary from theme to theme.
Categories are hierarchical, which means that each category can have subcategories. A news site could for example have the following category structure:
- North America
- Ice Hockey
In the example above, a post with the “Basketball” child category would also be displayed while viewing the archive page for the “Sports” parent category. You can edit categories in Posts → Categories.