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What is an API?

APIs are a key component in many of the apps on your phone, but what is an API? 

Keep reading to learn everything you need to know about APIs. 

What is an API? 

An API is a mechanism that allows two or more pieces of software to communicate and share data with one another. The term API stands for Application Programming Interface. 

A common example of this is the weather app on your smartphone. The app uses APIs to receive up-to-date data from the weather bureau’s software system and share that information with you through daily updates. 

Another popular example is Twitter/X’s API, which is available to use through its developer platform. In this instance, the API can be used to create bots, cross-post content, moderate conversations, gain insight into trends on the app and more. Twitter offers both a free Basic version of its API as well as a paid Pro offering with fewer limitations for businesses to build upon. 

APIs can be found across a variety of software and platforms and are instrumental in allowing them to communicate with one another and allowing developers to build new experiences faster.

How do APIs work?

“API architecture is usually explained in terms of client and server”, explains Amazon on its AWS website

“The application sending the request is called the client, and the application sending the response is called the server. So in the weather example, the bureau’s weather database is the server, and the mobile app is the client”. 

There are four different ways in which APIs might work depending on if they’re SOAP APIs, RPC APIs, Websocket APIs and REST APIs. However, the end goal is the same – to communicate with another application. 

Likewise, there are four types of APIs that are designed with different audiences and uses in mind. 

Private APIs are made to be used within a business, Partner APIs are used in business-to-business partnerships, Public APIs are open to the public (though not necessarily without authorisation) and Composite APIs are defined as a combination of two or more APIs.

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