API simplifies programming by abstracting the underlying implementation and only exposing objects or actions the developer needs. API is a way for two or more computer programs or components to communicate with each other. It is a type of software interface, offering a service to other pieces of software. APIs is to hide the internal details of how a system works, exposing only those parts that a programmer will find useful, and keeping them consistent even if the internal details change later. An API may be custom-built for a particular pair of systems, or it may be a shared standard allowing interoperability among many systems.