What is a RESTful API - A Confusion Clarification Guide

Hello developers! In this blog post, we will explore all about RESTful APIs, what they are, how they work, and why they are crucial in today's tech landscape.

When someone asks us, "Do you know REST APIs?" then when can we say we know REST API? I was also confused about this sometime ago, but now I am almost clear. I know REST API, and by writing this blog post, it becomes even more clear.

When we are able to build a system that exchanges data between two devices and/or performs some work on one device from another device by making a web request, then we can say we know about REST API and we can work with it.

For example, when we visit a website, the browser makes a request to the server. So, there is a server application that may be built using REST API.

What is a REST API

REST API is an architectural style for designing networked applications. It is based on a set of principles that define how resources are identified and addressed over the web. REST APIs use standard HTTP methods (GET, POST, PUT, DELETE) to perform CRUD (Create, Read, Update, Delete) operations on resources, making them easy to use.

The term "REST" stands for "Representational State Transfer." It is an architectural style for designing networked applications, particularly web services and APIs built on this style are known as RESTful APIs.

When we use the Fetch API in a web browser, we're typically making HTTP requests to interact with a server-side REST API. The server exposes RESTful endpoints that allow us to perform various actions, such as retrieving data (using HTTP GET), creating new data (using HTTP POST), updating existing data (using HTTP PUT or PATCH), or deleting data (using HTTP DELETE).

So, while we're not directly implementing the REST API architecture on the client side, but interacting with a server-side application that exposes RESTful API endpoints.

Where endpoint refers to a specific URL (Uniform Resource Locator) that represents a resource or a collection of resources. Each endpoint is dedicated to a particular CRUD operation (Create, Read, Update, Delete) or other actions that can be performed on the resource(s) it represents.

An endpoint may directly point to a static resource that returns when we hit the endpoint, fetch data from an external source and return and/or do some processing on the server like creating a PDF file with provided data, image transformations.

The following are key characteristics of REST APIs:

• Statelessness: Each request from a client to the server must contain all the necessary information, and the server does not retain any client context between requests.
• Uniform Interface: Resources are uniquely identified by URIs, and standard HTTP methods are used to interact with them.
• Client-Server Architecture: The client and server are separate entities, allowing them to evolve independently and scale effectively.
• Cacheability: Responses from REST APIs can be cached to improve performance and reduce server load.
• Layered System: REST APIs are composed of multiple layers, with each layer responsible for a specific aspect of the communication process. This enhances flexibility and scalability.

The following are some of the importance of REST API:

• Interoperability: REST APIs enable different software systems to communicate and exchange data seamlessly, regardless of the underlying technologies or platforms.
• Scalability: The stateless nature of REST APIs simplifies server implementation and enhances scalability, making them ideal for handling large volumes of requests.
• Flexibility: REST APIs allow us to design modular and decoupled systems, making it easier to update and maintain software over time.
• Integration: REST APIs facilitate integration between disparate systems, enabling organizations to leverage existing infrastructure while adopting new technologies.

We must follow the below best practices for designing REST APIs:

• Use Descriptive URIs: URIs should be meaningful and reflect the hierarchy and structure of the resources they identify.
• Follow HTTP Semantics: Utilize standard HTTP methods and status codes to ensure consistency and interoperability.
• Versioning: Implement versioning to manage changes to the API over time and ensure backward compatibility.
• Authentication and Authorization: Secure your API endpoints with robust authentication and authorization mechanisms to protect sensitive data.

We can perform different work using HTTP method other than the it's name express. For example, we can fetch a resource with the POST method, but it is best practice to use the GET method for fetching resources.

An API system that is built on the principle of REST is considered as RESTful APIs, whether it is built using any programming language and technology.

In the end, the point is that REST APIs are not a special type of APIs. It is the same as working with HTTP requests and responses. If we intracting with server without any SDKs, it means we working with RESTful APIs.

I hope you get some clarification about REST API. Happy Coding!