Digital Commerce is comprised of multiple packages as mentioned in the installation section and this section lists out the objects inside the package.

Object NamePurpose of the Object
StorefrontRepresents the storefront details.
Storefront BannerRepresents the storefront banner details.
Api CacheStores record information such as Line Item Ids and Attribute metadata for quick loading thus improving performance. When changes are made in the metadata of an object you are using, you should always clean the Api Cache objects.