We often come across the acronym API sprouting up in tech blogs and discussions. However, neither did many understand it well nor did they receive a lucid explanation from those who practice it. The fact is that it is not easy to explain an API (Application Programming Interface) in a few words. One simple way to put it across is to say that APIs are standards for the interchange of software application data, just as protocols are standards for the interchange of network data between computers.
In other words, an API is an intermediary that allows two software applications to talk to each other. Before the advent of APIs, software developers had to write code to get data or information from platforms or apps they want to access, a tedious and time-consuming process. A platform that provides APIs allows third-party software developers to embed them in their applications to provide and receive data from the platform. It also integrates platforms or applications to produce powerful results.
An API is a set of codes to receive requests from and send responses to other applications or programs to access the API-providing platform. Suppose you want to incorporate a map on your website or display a list of your latest social media posts, you can’t directly access Google Maps or social media like Twitter because you don’t have access to the code that runs Google and Twitter. But those platforms provide APIs that allow users to retrieve data from their sites if authorized by their servers.
The API of Google Map, social media, or bureau may be among the most widely used APIs, but most software-as-a-service (SaaS) providers offer APIs that allow software developers to write code that sends data to and receive data back from the SaaS provider’s site. API architecture is similar to that of client and server structure where the application sending the request is called the client, and the application sending the response is called the server. So in the weather bureau example, the bureau’s weather database is the server, and the mobile app that receives information from the weather bureau server is the client.
An application installed on your mobile phone or other devices connects to the Internet and sends data to a server, the server retrieves that data processes it and sends it back to the app on your mobile phone. The mobile app then analyses that data and shares the requested information with you in the format you understand. This is how an API works. Though APIs have been around since when network computing emerged, it has found wider applications after the rise of the internet and the Web. It was Salesforce that introduced the first web APIs in 2000. Government APIs allow service seekers access to information from government portals and Banking APIs facilitate Open Banking, Banking as a Service (BaaS).
Let us explain it with an example we can relate to. Imagine you are in a restaurant to order food that has to come from the kitchen, but you don’t go to the kitchen directly. You need an intermediary to take your order request, pass it on to the kitchen, and get the order delivered from the kitchen to your table. The intermediary here is the waiter, and that is exactly what an API does in the application. We will now look at a real-life API example. Most air travelers search online for flights by visiting the website of an airline. But if you have to consider and compare more options from multiple airlines, you have to visit the website of each airline. The solution is to use the app of airline travel services aggregators like MakeMyTrip or Yatra, which interact with the APIs of all the airline’s websites. The airline API is the interface that gets the information from the airline’s database for you to compare timing, fare, discount, etc, and make the decision to book the ticket of your choice.
There are basically four different ways that APIs can work depending on when and why they were developed, like SOAP API that exchanges messages between server and client using XML. RPC API under which the client completes the procedure on the server, and the server sends the output back to the client, or Websocket APIs that uses JSON Objects to exchange data. However, REST API is the most popular and flexible API found on the web today, where the client sends requests to the server as data, and the server processes the client's input and returns output data to the client. The origin of representational state transfer (REST) goes to a Ph.D. thesis by computer scientist Roy Fielding.
It was eBay that launched the first REST API in 2002, allowing external software developers to add value to eBay’s platform. Today, most APIs are REST-based APIs, whether it be for web-based services, social media, mobile applications, or hardware devices like the Internet of Things (IoT), among other platforms. While most APIs we know are public APIs (also called open APIs) that allow third-party applications to use your API, private APIs are used in certain circumstances for internal use cases.
These days, organizations have multiple systems running on different platforms including on the cloud. It is highly difficult or risky or expensive to have every requirement of an organization available on a single system. That said, disparate systems running in silos will only be creating chaos. In today’s fast-paced environment where quick data analysis and insights are a must to sustain and scale, the data has to be integrated and merged for better results. APIs play the role of application integration by enabling applications and systems from different vendors to involve each other in their workflows. An API integration serves as the connection between two applications to exchange data and automate data sharing in a secure process.
Depending on the type of your business, size, and requirements, you will need the APIs of other platforms to receive the required data. In the same way, others may need data and information from your application which will need you to have your API in place. Setting up a team to plan and execute an API project with an internal team can be time-consuming and less cost-effective. It may also happen that you will not get the best-fit talent for the duration you want them to be on board. This is where Task as a Service (TaaS) platforms come as a recourse for you to get such short-duration tasks executed easily and without hassles, at a lower cost.