In the dynamic landscape of web development, APIs (Application Programming Interfaces) play a pivotal role in enabling communication between different software applications. Among various types of APIs, REST API stands out as a widely adopted and efficient approach. In this blog post, we'll unravel the mysteries of REST API, exploring its basics, principles, and how it has become a cornerstone in modern web development.

What is REST API?

REST (Representational State Transfer) is an architectural style that was introduced by Roy Fielding in his doctoral dissertation in 2000. RESTful APIs, or simply REST APIs, adhere to the principles and constraints laid out by REST. These APIs are designed to be simple, scalable, and stateless, making them ideal for the web.

Key Principles of REST API:

Statelessness: Each request from a client to a server must contain all the information needed to understand and fulfil the request. The server should not store any client state between requests.

Client-Server Architecture: The client and server are separate entities that communicate over a network. This separation enhances scalability and simplifies maintenance.

Uniform Interface: REST API enforces a uniform and consistent interface between components. This includes resource identification, manipulation using representations, and self-descriptive messages.

Resource-Based: REST treats data as resources identified by URLs. These resources can be manipulated using standard HTTP methods like GET, POST, PUT, and DELETE.

Representation: Resources are represented in different formats, such as JSON or XML. Clients interact with these representations to perform operations.

How REST API Works

REST API relies on standard HTTP methods for communication. Each resource is identified by a unique URL, and these resources can be manipulated using the appropriate HTTP methods.

• GET: Retrieve information about a resource.
• POST: Create a new resource.
• PUT: Update an existing resource.
• DELETE: Remove a resource.

For example, to retrieve information about a user with the ID 123, the URL might be https://api.example.com/users/123 using the GET method.

REST API works as a communication between two systems, sharing the data from one system to another system and vice versa. 

The Basic steps for processing REST API, 

• A system (let’s call it a front-end web application) sends a request by calling the REST API URL. 
• Another system (let’s call it a backend web application) parses the request based on the data received from the front end and the URL pattern. 
• The backend system returns the data to the frontend system as an HTTP response with JSON data

Benefits of REST API

• Scalability: REST API's statelessness and simplicity contribute to easy scalability.
• Flexibility: Supports multiple data formats, making it flexible for different applications.
• Simplicity: Easy to understand and implement, reducing development time and effort.
• Compatibility: Compatible with various programming languages and platforms.

Let’s understand and get a basic idea of the workings of the REST API by a simple example.

Examples

Ordering in Restaurant

Let’s understand it with the restaurant example. If you visit a restaurant, you interact with the waiter to order your food.

The key persons are you (front-end), a waiter (REST API) & the restaurant (back-end). You give your order to the waiter, wait for your order and it’s delivered to you.

Courier Service

Another example is the courier service. In this case, the sender sends a parcel and that parcel is delivered to the doorstep of the receiver and the sender gets a message of successful delivery.

In this case, the sender is the front end, the receiver is the backend and the courier service being used is the REST API.

In conclusion, REST API has become the backbone of modern web development, providing a standardised and scalable way for applications to communicate. Understanding its principles and how it works is essential for any developer building web-based systems.

Now that you've grasped the basics of REST API, consider implementing it in your projects to enhance interoperability and efficiency.