What is an Application Programming Interface (API)?

The application programming interface concept

The term API stands for Application Programming Interface.

An application programming interface (API) is a code that allows two software programs to communicate. An API defines how a developer must request services through an operating system (OS) or other application. It also defines how to expose data in different contexts and across multiple channels.

All types of data can be shared via an application programming interface. APIs are implemented by function calls consisting of verbs and nouns. The required syntax is defined by the contacted application.

A few years ago, the concept of integrating data and applications from different sources was called a mashup. The web, data exchange software and cloud computing have all contributed to increasing interest in APIs since that time.

How do APIs work?

APIs consist of two related elements:

a specification describing how information is exchanged between programs (in the form of a processing request followed by a return of necessary data);
a software interface written to this specification and ready for use.

The software that wants to access the features and capabilities of the API is described as the caller, and the software that creates the API is described as the publisher.

APIs allow and allow access to data as requested by users and other applications. Access is authenticated to a service or functionality using predefined roles. These govern who can access specific actions and data.

APIs also provide a detailed list of accesses that detail and usage. It includes a list of the users who had access to the system and when.

Applications that call APIs used to use specific programming languages. Web APIs can now be called by any programming language. Thus, Web pages created in hypertext markup language (HTML) or application generator tools can also access them.

The most common API structures are called Representational State Transfer (REST) and Simple Object Access Protocol (SOAP). They define a standard communication protocol specification for exchanges based on Extensible Markup Language (XML).

Updated on: 12/05/2023