Application programming interface (API)

A set of definitions that you can make use of in writing programs. In the context of Java, these are the packages, classes, and interfaces that can be used to build complex applications without having to create everything from scratch.

A programmatic interface that enables software developers to access features and functions of a hardware or software platform. An API is the specific method prescribed by a computer operating system or by an application by which a programmer writing an application program can make requests of the operating system or another application.