Application Programming Interfaces (APIs) have completely overtaken how we use mobile and web applications by allowing software to interact with other software. Today, we use APIs as a key entry point for any data, service, and integration access.
An API is an interface that allows two pieces of software to communicate with each other. It provides a way for one program to request data from another program, and for the other program to respond to that request.
An API can be thought of as a set of rules that govern how two pieces of software interact with each other. When one piece of software wants to request data from another piece of software, it does so by following the API's rules. The API then tells the second piece of software how to respond to the request.