In Core Commerce, the product catalog is called a repository, and the elements of the catalog (such as folders, categories, products, and images) are repository items. You build the product catalog by adding new repository items and defining relationships between them.

The catalog item type represents different versions of your store for customers to shop in. Categories are like store departments, and products represent the individual products for sale. SKUs represent different versions of the product, and are the actual items sold. For example, a product that represents a specific shirt might have many associated SKUs, representing different combinations of size and color. Folders are used for organizing items in the catalog.

Core Commerce also has media item types, which represent the JSP template pages used in the site, and images, which can be displayed along with categories, products, or SKUs.