Catalog-to-store assignment and catalog sharing across stores
Key Takeaway
A store can have only one catalog at a time, but one catalog can be assigned to many stores. To let another store sell from an existing catalog, assign that catalog to the store with "Assign Store" on the catalog's "Stores" tab.
In B2B Commerce, a catalog is the entire collection of products that a store offers. A store needs a catalog before buyers and shoppers can see any products. Each store uses one catalog at a time, but you can assign one catalog to several stores so they share the same products.
What a catalog is
Your store must have a catalog before you can make products available to buyers and shoppers.
Inside a catalog, products are grouped into categories so buyers can find them more easily. A product is assigned to a category. Each category is assigned to a catalog.