Difference decoupled and headless

Hi,

We are starting a new project in BrXm 14. Now we are checking what the difference is between decoupled and headless. But as a developer I don’t really get what the differences are exactly.
Is there someone that can give me the differences maybe with an example?

Thank

it is described here:

The architecture of headless and decoupled is quite similar - both feature a separation between the content repository at the backend and the publishing tools at the frontend.

Decoupled CMS, however, comes with a built-in API that handles the front end, eliminating the need to build a custom-made API.