APIs (Application Programming Interfaces) are how different software applications talk to each other. If you are building a website or app that needs data from a server, you are using an API. Two main approaches dominate today: REST and GraphQL. Let me explain both.
What is an API?
An API is a set of rules that lets different software communicate. Think of it as a waiter in a restaurant — the customer (your app) tells the waiter (the API) what they want, and the waiter gets it from the kitchen (the database) and brings it back. APIs standardise how this conversation happens.
REST APIs
What is REST?
REST stands for Representational State Transfer. It is an architecture style that uses standard HTTP methods. REST APIs have been the standard for over a decade and are simple to understand.
How REST Works
REST uses HTTP verbs to perform actions:
- GET — retrieve data
- POST — create new data
- PUT — update existing data
- DELETE — remove data
REST Example
To get a user from a REST API, you make a GET request to: /api/users/123
The server responds with the user's data. To create a new user, you POST to /api/users with the new user's details.
REST Pros and Cons
GraphQL APIs
What is GraphQL?
GraphQL is a newer query language for APIs. Instead of fixed endpoints, GraphQL lets the client request exactly what data it needs.
How GraphQL Works
With GraphQL, you send a query that describes exactly what data you want. The server responds with only that data.
GraphQL Example
Instead of calling multiple endpoints, you send one query asking for specific fields:
query {
user(id: 123) {
name
email
posts {
title
}
}
}The response contains only the fields you asked for — nothing more, nothing less.
GraphQL Pros and Cons
REST vs GraphQL: Which to Choose?
REST is still the most popular choice for most projects. It is simple, well-understood, and works well for straightforward APIs. GraphQL is excellent for complex applications where clients need flexibility — think social media apps, dashboards, or mobile apps with limited bandwidth.
Real-World Examples
- REST: GitHub API, Twitter API, weather services
- GraphQL: Facebook, Shopify, GitHub (also has GraphQL API)
The Future
Many companies are moving toward GraphQL because it is more efficient for client applications. However, REST is not going away. Smart companies often offer both — REST for simplicity and GraphQL for power users.
Getting Started
Want to build your own API? Start with REST using Express (Node.js) or Flask (Python). Both are beginner-friendly and teach you the fundamental concepts. Once you master REST, learning GraphQL becomes much easier.