What is an Application Programming Interface (API) ?
In programming, an API (Application Programming Interface) is a set of subroutine protocols, definitions, and tools for making application software.
An application programming interface, better known as an API, is a tool that allows programmers to achieve a single goal. APIs usually contain at least one tool, such as a language library, and are often combined with other tools in software development kits, or SDKs. An application programming interface might be built for use within an organization, or it could be built for the customers of a company to use.
Why Do Application Programming Interfaces Matter?
An application programming interface is important for a number of reasons. Perhaps the most vital is that it makes creating programs simpler and easier. Essentially, an API contains the building blocks needed to create a program – the protocols, routines and tools necessary to create a specific type of software. Note that while this sounds similar to what SDKs do, it is not the same. SDKs might contain APIs, but APIs do not contain SDKs, nor are they as comprehensive or robust as SDKs.
Essentially, APIs allow functionality between two different applications. For instance, let’s say you have a Word document open on your desktop, as well as an Excel sheet. You copy text from the Word document and paste it into a cell in the Excel spreadsheet. The fact that you can do that at all is because APIs are working in the background to communicate between the two different applications. The same thing happens when different web apps communicate with one another.
For instance, let’s say that you run a doctor’s office, and you want your patients to be able to schedule appointments online, using Google Calendar. You build a web page that allows patients to choose the day and time of their appointment, and then the web page communicates with Google Calendar through an API when they do so. Google Calendar returns a confirmation when the information has been successfully entered, telling your patient that their appointment has been scheduled.
To further illustrate what an application programming interface is and the many ways with which people interact with them today, even if they don’t realize it, let’s look at a few popular examples.
Twitter: Twitter’s primary API allows access to search and trending data, and another allows access to core data within the social network.
Amazon: Amazon’s API allows the creation of everything from specific web stores to product discovery and even advertising solutions through the retail giant.
Google Maps: Google Maps’ API allows maps to be embedded in websites, social media pages and in other areas, and for users to interact with those maps without actually having to run Google Maps themselves.
As you can see from the information above, application programming interfaces, or APIs, provide important communication capabilities, interconnectivity and other benefits that today’s Internet and software users have come to take for granted. It is important for software developers to not only understand how an API works, but how important connecting through APIs is to functionality within the software they’re developing.