A connection between computers or computer programs is known as an application programming interface (API). It is a form of software interface that provides a service to other programs. An API specification is a document or standard that defines how to create such a connection or interface. An API is implemented or exposed by a computer system that meets this standard. The term API can be used to refer to either the specification or the implementation.
APIs are now a part of practically everything we do on the internet.
When a developer adds an endpoint to a URL and makes a call to the server, this is known as an API request.
An API endpoint is a location where an API links with the software program. APIs work by sending and receiving requests for information from a web application or web server.
A technical writer that develops documentation that defines an application programming interface is known as an API writer.
API Testing is a sort of software test that verifies APIs. The goal of API testing is to ensure that programming interfaces are functional, reliable, fast, and secure. Instead of using typical user inputs (keyboard) and outputs, API Testing employs software to make API calls, get output, and record the system’s response.
Authentication is the process of determining an end user’s identity. Basic authentication in a REST API can be done with the TLS protocol, although OAuth 2 and OpenID Connect are more secure options.
Authorization is the process of determining which resources a specific user has access to. To restrict users from accessing API methods or actions outside of their predefined role, an API should be designed and tested. A read-only API client, for example, should not be able to access an endpoint with admin functionality.