Shopify is not a headless CMS. A headless CMS is a backend only Content Management System (CMS). A headless CMS provides content through APIs or headless browsers, which are used by front-end developers to build the user interface and UX. Shopify, on the other hand, is a fully-fledged eCommerce platform that includes a CMS. While Shopify does have an API that developers can use to build custom front-ends, it also has its own templating language and set of themes that can be used to build a complete online store.