What is the full form of API

API: Application Programming Interface

API stands for application program interface. A programmer writing an application program can make a request to the Operating System using API (using graphical user interface or command interface). It is a set of routines, protocols and tools for building software and applications. It may be any type of system like a web-based system, operating-system or a database System.

Usage

API in Procedural languages

It specifies a set of Functions and Routines that helps in completing a task.

API in object-oriented languages

It simply shoes how an Objet work in a given Object-Oriented language. It is expressed as a set of classes with an associated list of class Methods.

API in libraries and Frameworks

It is related to Software libraries and Software Framework.

API and Protocols

It can be implementation of Protocols.

API sharing and reuse via virtual machine

Languages running on virtual machines can share can share an API.

API Designs

Several principles are used in designing of API's. One method is the concept of information hiding. It works on the principle that a software can be divided into modules, each of which has a specified interface.

Another is software architecture which is used to create and maintain high-level software structures.