What is an API?
APIs are how software applications talk to each other.
The Restaurant Analogy
Imagine you're at a restaurant. You don't go into the kitchen to cook your food—instead, you use the menu to see what's available, tell the waiter what you want, and receive your meal.
Menu = API
Defines what operations are available and how to use them
Kitchen = Server
Processes your order and prepares the response
You = Client
Makes requests and receives responses
API = Application Programming Interface
An API is a contract between two pieces of software. It defines:
- What operations are available (endpoints)
- What data to send (request)
- What data you'll get back (response)
- How to authenticate (if needed)
Why APIs Matter
🔗 Integration
APIs let different applications share data. Your weather app gets data from a weather API, not by running its own satellites.
🧩 Microservices
Large applications are built from smaller services that communicate via APIs. Netflix, Uber, and Amazon all use this architecture.
📱 Multi-platform
One API can serve web, mobile, and desktop apps. Build your logic once, access it from anywhere.
🔐 Security
APIs act as a controlled gateway. The client never accesses the database directly—only through the API.
What You'll Learn
In this interactive guide, we'll explore different types of APIs:
Try It: Your First Request
Click the button below to send your first API request. We'll hit a demo endpoint that returns a greeting.