Based on representational state transfer, a REST API is an architectural approach and style for communications used in web services development. REST APIs are also known as RESTful APIs and RESTful web services. Developers generally prefer using REST technology over the other most popular alternative, Simple Object Access Protocol, because the former uses less bandwidth.

That means it is more efficient for internet use. And with cloud use on the rise, REST APIs are the ideal choice for enabling end-users to connect, manage, and interact with web and cloud services in a distributed environment. Well-known platforms like Google, Amazon, and LinkedIn use REST APIs.

How do REST APIs work?

In basic terms, a REST API breaks down a transaction into small manageable modules. Each of the modules addresses a specific underlying element of the transaction. That enables developers a great deal of flexibility. However, it can be challenging for developers to design a REST API from scratch. If you are unsure how to begin, check out these excellent API tutorials from RapidAPI.

REST APIs use HTTP methodologies, which are defined by the RFC 2616 protocol. Basically, REST APIs use GET to retrieve resources and PUT to alter or update the status of a resource such as an object or a file. POST is used to create the resource, and DELETE is used to remove it.

How are REST APIs used?

With the growing development of cloud computing and microservices, REST APIs are starting to be used more and more by developers. The calls of REST APIs are restless, which makes them ideal for cloud applications and web use.

If something fails, stateless components can be freely redeployed. They can also be scaled to accommodate load alterations. That is because any request can be directed to any instance of each element. Nothing needs to be saved for the next transaction.

REST API Design and Architectural Constraints

In order to be a true REST API, web services must adhere to six REST architectural constraints. Here is an overview of each one.

REST Resource Caching

Every resource should enable caching unless it is specifically indicated that caching is not possible.

Layered System

REST enables an architecture that is composed of multiple layers of servers.

Uniform Interface

Resources need to be uniquely identifiable via a single URL while only using the network protocol’s underlying methods. For instance, protocols such as GET, PUT, and DELETE with HTTP enable you to manipulate a resource.


There needs to be a clear delineation between the server and the client. Things like UI and request-gathering are within the client’s domain. Things like data access, security, and workload management are within the server’s domain. The two distinctions allow each to be developed independently of one another.

Stateless Operations

Every client-server operation needs to be stateless. Also, any state management you require should occur on the client, not on the server.

Code on Demand

A server typically sends back static representations of resources in formats like JSON and XML. But when necessary, servers are able to send executable code to the client.