A Decoupled CMS has the publishing tools of traditional content management, meaning it has a frontend layer and frontend development tools are available right out of the box. The architecture clearly separates the management and storage of content from the pages and templates that display it. That is, the presentation (frontend) is decoupled from the backend. The two layers communicate via APIs. A set of endpoints expose the content to one or many consumers, from websites that can be developed with the built-in toolset (widgets, templates and the like) to various platforms and frontend frameworks that can take in and interpret the data in the API responses. A decoupled CMS lets you opt between the inherent presentation layer and various headless implementations with a frontend technology of choice. Sitefinity is decoupled by design.