From Joomla! Documentation
Category Options control how articles will show when you drill down to a Category to view its articles.
- Choose a layout. (Blog/List/user defined). This lets you select the default layout to show when you click on a Category link. If you create an alternative layout for a category layout, you may select that as the default.
- Category Title. (Hide/Show) Hide or Show the title of the category.
- Category Description. (Hide/Show) Hide or Show the description for the category.
- Category Image. (Hide/Show) Hide or Show the category image.
- Subcategory Levels. (None/All/1-5). Categories in Joomla can be created in a hierarchy. This lets you control how many levels of subcategories to show when showing a category view.
- Empty Categories. (Hide/Show) Hide or Show categories that don't contain any articles or subcategories.
- No Articles Message. (Hide/Show) If Show, and if Empty Categories is Show, a message "There are no articles in this category" will show if a category contains no articles.
- Subcategories Descriptions. (Hide/Show) Hide or Show the descriptions for subcategories that are shown.
- # Articles in Category. (Hide/Show) Hide or Show a count of the total number of articles in each category.