Introduction to APIs and API Testing

In today’s tech-driven world, APIs (Application Programming Interfaces) are everywhere. They connect different software systems, allowing them to “talk” to each other and share information seamlessly. If you’ve ever used an app that retrieves weather data, processes a payment, or connects to social media, chances are you’ve interacted with an API without even realizing it.

But what exactly is an API? And what does it mean to test one? Let’s break it down.

What is an API?

An API is a set of rules that lets two systems communicate. Imagine APIs as waiters in a restaurant. When you place an order (make a request), the waiter (the API) delivers your request to the kitchen (the server). The kitchen processes the order and sends the food (response) back to you via the waiter. Similarly, an API allows applications to request data from a server and get responses back, all without needing to know the inner workings of the server.

For example:

Google Maps API allows websites or applications to embed maps and geographical data.
Twitter API enables apps to post or retrieve tweets.
What is API Testing?
API testing ensures that APIs function as expected. Instead of testing the UI (what the user sees), you’re testing the API directly to make sure it: