What is a REST API?

RESTful web services are loosely coupled, lightweight web services that are particularly
well suited for creating APIs for clients spread out across the internet.

A REST API (Representational State Transfer Application Programming Interface) is a type of web service that uses HTTP requests to GET, POST, PUT, and DELETE data. REST APIs are typically used to retrieve, add, or change data in a database, and are often used in web and mobile applications.

The REST architectural style is designed to use a stateless communication protocol, typically HTTP.

REST APIs use standard HTTP methods to communicate with other web services and systems, which makes them easy to use and widely supported.

REST Representational State Transfer (RESTful) web services. they are second-generation Web Services.
RESTful web services, communicate via HTTP than SOAP-based services and do not require
XML messages or WSDL service-API definitions. for REST no middleware is required only HTTP
support is needed.WADL Standard, REST can return XML, plain text, JSON, HTML, etc

Resource identification through URI

A RESTful web service exposes a set of resources that identify the targets of the interaction with its clients. Resources are identified by URIs, which provide a global addressing space for resource and service discovery.

Uniform Interface

Resources are manipulated using a fixed set of four create, read, update, and delete
operations: PUT, GET, POST, and DELETE. GET retrieves the current state of a resource in some representation. POST transfers a new state onto a resource. PUT creates a new resource, which can be then deleted by using DELETE.

Self-descriptive messages

Resources are decoupled from their representation so that their content
can be accessed in a variety of formats, such as HTML, XML, plain text, PDF, JPEG, JSON, and other
document formats.

Every interaction with a resource is stateless, that is, request messages are self-contained

HTTP Methods

REST APIs use a number of HTTP methods to perform different actions, such as

  • GET to retrieve data
  • POST to create new resources
  • PUT to update existing resources
  • DELETE to delete resources.

These methods, along with the URI (Uniform Resource Identifier) of the API endpoint and the HTTP status codes returned by the API, form the core of the REST API design.

Uniform Interface

One of the key features of REST APIs is that they use a uniform interface, meaning that all API endpoints adhere to a common set of rules for requesting and returning data. This makes it easy for developers to understand and use REST APIs, as well as for API clients (such as web browsers or mobile apps) to consume them.

Easy Client Integration

One of the benefits of REST APIs is that they can be consumed by any client that can make HTTP requests. This makes them ideal for building APIs for web, mobile, and other types of applications. REST APIs can also be easily integrated with other systems and services, making them a popular choice for building microservices and other distributed architectures.

Ease Of Testing

In addition to their flexibility and scalability, REST APIs are also easy to test and debug. Developers can use tools such as Postman to make API requests and examine the responses, making it easy to troubleshoot issues and optimize the API.


Overall, REST APIs are a powerful and popular tool for building modern, distributed systems. Whether you are building an API for a web application, mobile app, or another type of system, REST APIs can provide a reliable and flexible way to retrieve and manipulate data.