Understanding REST APIs: A Beginner-Friendly Guide

Introduction

Modern web applications constantly communicate with servers to fetch or update data. For example, when you open a social media app or check the weather on your phone, your device sends a request to a server and receives information in return.

This communication usually happens through REST APIs.

In this article we will understand:

• What a REST API is

• How REST APIs work

• Common HTTP methods used in REST APIs

• A simple example using backend development

What is a REST API?

REST stands for Representational State Transfer.

A REST API is a way for applications to communicate with each other over the internet using HTTP requests.

Example request:

GET /users/1

Example response:

{
 "id": 1,
 "name": "Yuva"
}

The server sends data in JSON format.

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Common HTTP Methods

GET

Used to retrieve data.

Example:

GET /users

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POST

Used to create data.

POST /users

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PUT

Used to update data.

PUT /users/1

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DELETE

Used to remove data.

DELETE /users/1

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Example Using Spring Boot

Example API in Java Spring Boot:

@GetMapping("/users/{id}")
public User getUser(@PathVariable int id) {
    return userService.getUserById(id);
}

This API returns user information based on the given ID.

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Why REST APIs Are Important

REST APIs are widely used because they are:

• Simple

• Lightweight

• Scalable

• Easy to integrate

Most modern applications rely on REST APIs for communication between services.

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Conclusion

REST APIs allow applications to communicate using HTTP methods like GET, POST, PUT, and DELETE.

Understanding REST APIs is essential for backend developers and anyone interested in web development.

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