Storefront / Headless Commerce Engine — A storefront or headless commerce engine powers the self-serve buying experience — product pages, carts, and purchase flows — via your own frontend on commerce APIs. The catalog and localized price books feed it, and completed orders flow straight into billing and provisioning.
Storefront / Headless Commerce Engine lives in the Digital Commerce phase of Win the Deal — the stage where you quote, negotiate, and close on governed pricing. In the corpus tool index this phase maps to the Payments and Billingcategories.