API services & MVC
MVC (or Model-View-Controller) is an architectural pattern on which to build software. The basic idea in it is to separate internal data models from the user interface via the controller and view. It is dominating web and mobile development, and although some alternatives exist, almost all relevant server-side software is developed with an MVC-compliant (or an MVC-variant-compliant) framework. The thing is, MVC is made for full-stack development, where the software consists of the database, user interface and business logic.