What Is a Graphics API?

An Application Programming Interface (API) defines the way that applications interact with components of a computer system. In the case of a graphics API, this interface is typically implemented by driver software that is written by graphics hardware vendors.

By having a standard API, applications can be written so that they work with many different kinds of graphics hardware. For example, the same app will run on a Samsung Galaxy S7 no matter which vendor supplied its GPU design, because the graphics drivers for each type of hardware presents the same API to the application, even though the underlying GPU hardware architecture is very different.