Translations:Understanding categories and articles/12/en
From Joomla! Documentation
Other Types of Categories
There is also a potential for confusion about categories. Categories are also used by other components, including Banners, Contacts, News Feeds, and Weblinks. These categories are completely different from Article categories and are set up in different screens in the back end of Joomla!. So when you see something about categories, it might refer to Article categories or it might refer to categories for these other components.