Product category hierarchy and product-to-category assignment
Key Takeaway
Each product and category pair needs its own ProductCategoryProduct record, and the record with IsPrimaryCategory set to true decides the breadcrumb path.
In a B2B Commerce store, products are organized in a catalog that holds a tree of categories and subcategories. Categories control how buyers navigate and search, because they group similar products that buyers can find through navigation menus, search results, and filters. A product becomes available in a store only after it is assigned to a category, so setting up a store includes assigning its products to categories.
From store to product
The structure runs from store to catalog to categories to products. Each store connects to exactly one catalog (ProductCatalog). Each category (ProductCategory) belongs to only one catalog.
When you create a store, you get a default catalog named after the store, for example MyStore Catalog. The default catalog contains one default category called Products. Of the records created with a new store, the default category is the only one you can delete.