Everything You Need To Know About an API

If you are into the computing world, you probably have come across the term API at some point. Operating systems, applications and web browsers often announce APIs for developers.

What Does an API Refer To?

API is an interface between one software component to another. With APIs, programs can communicate with each other with no user intervention. Short for application programming interface, it specifies how these components should interact.

An example of a facility that uses an API would be online movie ticketing. When purchasing film tickets online, you always need to enter your credit card details. By entering that information, the ticketing service website utilizes an API in order to send that data to a remote program, which then verifies the info. After the payment is confirmed, that program will then send a response to the ticketing website authorizing the purchase of that ticket.

You’re the only user who can see the ticketing site but, in the background, many programs work together with these APIs. Such integration is seamless because you never notice when multiple software functions are passed from one program to another. One thing to note is that some companies use the name of their APIs to describe the specification of those interactions mentioned above and the software component we interact with. For instance, Twitter API refers to both sets of instructions for interacting with Twitter in a programmatic way and the thing we interact with.

APIs Make It Easier For Developers to Do Their Work

Here’s a scenario, you have always wanted to develop an application for the iPhone and now you finally decide to do it. The operating system of Apple, iOS, offers numerous application programming interfaces that will facilitate you in this process.

If you wish to embed an internet browser to display one or more pages, for instance, you do not need to program your browser from the ground up, just for the application you want to build. You can utilize the WKWebView API for embedding a WebKit browser object in that app.

If you wish to capture video or photographs from the camera of your iPhone, you don’t need to write your camera interface. Instead, you can use the camera application programming interface to embed the built-in camera of iPhone in your application. If there was no application programming interface, application developers would need to make their own camera program as well as interpret the camera hardware inputs. However, iOS developers have already taken a great deal of effort, so app developers can just utilize the camera API for the embedding process, and proceed with building their application. Besides, when Apple improves the API, every application relying on it will automatically take advantage of it.

This applies to all platforms. For instance, do you wish to make a dialog box for Windows? If you do, you will be glad to know that there is an application programming interface for that purpose. As a developer, you do not need to waste a great deal of effort to make something that already exists.

Application Programming Interfaces Control Access to Computer Resources

APIs are used to regulate access to both hardware units and software functions, which an app may not have permission to access. That is why application programming interfaces play a huge role in security. For instance, if you have been to a website, and encountered a notification in your web browser of that site asking for your exact location, it is trying to use your browser’s geolocation API. Internet browsers expose such APIs to facilitate in accessing your location – the website can ask for it to you and your browser will access nearby Wi-Fi networks or GPS to find it.

However, web browsers also expose that information through an API because access to it can be controlled. When a website needs access to your precise physical location, it can only get it through the location API. When a site tries using it, the user can decide to deny or allow this request. Hardware resources such as the GPS sensor can be accessed only through the API. Therefore, the web browser can also control access to that hardware device and limit what applications can do.

The same principle is being used on Android and iOS, where mobile applications have permissions enforceable by regulating access to application programming interfaces. For instance, if an app developer tries accessing the camera through the camera interface, the user can deny the request for permission, and then the application will have no way to access their device camera. File systems using permissions, as these do on Linux, Mac and Windows, have those enforced by the API of the file system. A typical app has no direct access to your raw hard disk; rather, the program must access the files stored in the hardware through an interface.

How APIs are used for communication

Application programming interfaces are also used for all sorts of other purposes. For instance, if you have seen any Google Maps object being embedded on a site, that site uses the Maps interface to embed it. Google exposes such APIs to developers of web applications, who can then utilize these interfaces to place complex objects on their site. If there was no API, developers might need to make maps and offer map information of their own just to place an interactive map object on a site.

Because it’s an application programming interface, Google can also control access to their Maps on websites of other entities. This makes sure that third-party websites use it consistently, rather than messily embedding a frame, like for instance, one which shows Google Maps’ site.