What is an API?

Application Programming Interfaces, or APIs, are sets of requirements and conditions that govern how one application can talk to another. They allow different applications to communicate without caring about what programming languages and platforms were used to create them. 

What is an API in web development?

In web development, many software vendors create APIs to allow third-party applications to access functionality and data in a secure way. 

This has the advantage of providing pre-existing functionality to teams so they don’t have to reinvent the wheel when putting applications together.

API Examples

The best way to understand what an API does is through real-world scenarios. Here, we look at three commonly used examples.

1. Bus Timetable
   So when are you using APIs? Have you ever checked live bus times on your phone? Or monitored traffic during rush hour? If you answered yes (you did), you’ve been using APIs for years and it’s been pulling data to make sure you get home on time!
2. Amazon
   The API is the middleman – it creates a handshake between the software you use and the data you need. This gives users the data they need for a specific purpose. Say you want to create a blog that reviews travel gear. After waxing lyrical about a certain backpack – you decide that you would like your readers to buy this item on your site. Using Amazon’s API – which allows you to access product information – all of your avid readers will be able to purchase from your blog! Adding a whole new layer of interactivity to your blog. 
3. Movie Tickets
   An easier example of an API working its magic is when you buy movie tickets online. When you select the movie and enter your credit card details, an API will transmit data to another app that verifies your information and processes the payment. Once confirmed, the verification application allows the tickets to be released. 

How is an API different from a web page? 

An API is a public persona for an organisation or even part of an organisation, that exposes assets, data, or services for public consumption. They allow organisations to open up data to external third-party developers, business partners and their own internal departments. 

A website is also a public persona for an organisation. The difference between an API and a website is that a website is designed for human viewing and consumption. An API is designed to be directly consumed by another piece of software running somewhere on a network. You interact with a website via a browser, but you interact with an API via code.

A website provides information on demand. A company puts content out in the world, and people consume it. Websites have no contracts or structures around the use of content.

If the content on the website changes, the next visitors get the new content. Their browsers aren’t affected, and any change is transparent to the user.

If you dramatically redesign the website, the only impact is on the user accustomed to seeing the content laid out in a particular way. 

API Contract

An API Contract is where you declare how your API behaves. Programs are built on top of that contract. If you alter anything in the contract of the API, the ripple effect on the apps built on top of it is potentially quite large. Hence the term contract. 

Once such a contract is in place, developers are enticed to use the API because they know they can rely on it. The contract increases confidence, which increases use. The contract also makes the connection between provider and consumer much more efficient since the interfaces are documented, consistent, and predictable. 

How popular are APIs?

The number of APIs has increased significantly. According to The News Stack, there are now more than 24,000 APIs. This is thanks in part to the emergence of the Internet of Things (IoT). APIs are at the heart of the IoT – without them, communication between different-purpose built devices would be troublesome. 

Many of the big players – including Google, Twitter, Facebook – have their own APIs that anyone can use. With the Google Maps API, you can access all the great functionality of Google Maps and integrate it into your own website or mobile application. Next time you’re house hunting, searching for local eateries or if you’re still hunting tiny monsters on Pokemon Go – be sure to thank Google Maps for the assist! 

APIs have pervaded every industry as companies continue to open up the valuable data they’ve collected on customers. This shift in thinking is helping companies to innovate faster and encourages growth. Adding features and functions to an application has never been simpler, thanks to APIs. They’ve changed the shape of every industry and have become an integral part of application development.

Learning to Code and APIs

As part of Code Institute’s Full Stack Software Development with Specializations programme, students learn how to interact with APIs. If you’re new to software development and want to learn some of the basics for free, then try our 5 Day Coding Challenge. After one hour a day over five days, you’ll have built your first web page. Register now through the form below.