Categories organize your catalog into a hierarchy that provides a navigational framework for your Web sites. Categories can be parents to catalogs, products, or other categories.
A category can be either the child of one or more other categories or a root category. A root category is a starting point in the navigational structure of the catalog. A catalog can contain more than one root category, but only one can be the navigation root. For example, a catalog could contain the following root categories:
Commerce Root Category, which contain all the catalog’s categories, products, and SKUs.
Non-Navigable Root Category, which contains assets that can be purchased but are not included in navigation, like gift wrapping.
See Category Properties for more information.
Note: A category can directly belong to multiple catalogs, making it easier for a category to be part of more than one site in a multisite environment.
