Definition: API

API (Application Program Interface) is a software middle-box that allows communication between two applications and allows different components of an application to interact with one another. APIs are used for simple tasks like checking the weather on your phone.

Let’s say that you use an application in your smartphone that requires internet connectivity. The application connects to the internet and sends data to the relevant server. The server receives the message, interprets and processes it, and sends the required data back to your smartphone. The application in your phone interprets the data received from the server, extracts the required information, and presents it to you in a readable format. The entirety of this process is done via an API.

Over the years, APIs have transformed and have acquired some features that make them even more efficient and useful. Modern APIs conform to HTTP standards, which makes them developer-friendly and easy to understand. More standardization also means that APIs can be better monitored for security and managed for performance and scalability issues. Most modern APIs are very well documented in order to be understandable to even a novice user.