What is an API? Why you need to know about an API?

API stands for Application Programming Interface.

In General Term API is programming interface using which two computer communicate with each other. Although API is way back to 1940 when modern computer was not invented, but we don’t really need to go that much back.

Unfortunately I am not professor otherwise I will give below definition to an API.

“It’s a piece of software that provide certain information or perform some calculation based on provided instruction and command. “

Don’t take my definition seriously, API is very broad topic we will understand it step by step.

Understanding API with real life example

It’s an 8:00 PM, your loved one get very hungry so you take her to a beautiful restaurant. After you find your place; waiter comes to you and with gentle voice said “How may I help you? “. You read a menu items and give your order, He took your order and forward it to a kitchen. Where your order actually get prepared. After some time your order get prepared and it’s serve to you.

In above example waiter is link between your order and kitchen. You don’t have to give direct order to a kitchen. API works exactly like a Waiter. API takes your instruction and pass it to the System. System process your instruction and send back a result.

In your daily life you are using power of API unknowingly, how? Let’s give me some examples to give more clear idea.

  • When you open your Facebook and click like button or make a comment on post, internally its call an API and update it on Facebook.
  • When you send a message on WhatsApp to your friend or Group
  • When you see a weather Broadcast news on your mobile
  • When you click a camera button of mobile and captured a photo. (Its call Operating System API)
  • When you check an air ticket rate of different flights from Laptop Browser
  • When Uploading a reel on Instagram
  • When you check your bank balance from mobile
  • If you are a programmer than you surely know with every programming language it’s provide sets of API for communicating with some internal layer.
  • On Hotel booking site when you compare Hotel pricing
  • When you send money from your wallet to your friend.

Why you need an API?

I am software developer by a profession, I comes across lots of requirement per Month. Although most of my clients have technical background so I don’t have to explain them what is an API and why we need it. They know importance of it. But many time it happens client have specific requirement sets but unknown about some of the important specs that is necessary for a development.

Let’s take an illustration of this basic real life case that I come across once a Month and this is motivation behind writing this blog too.

Let’s take an illustration of this basic real life case that I come across once a Month and this is motivation behind writing this blog too.

One of our client wants a Mobile application, Primary purpose of app is to show handpicked stocks by client from NYSE (New York Stock Exchange) and showing daily updates to his valuable customer. There are couple of screens like Login, Registration, and Dashboard which show a graphs, a handpicked stock by client for showing its statistics and profile page. Client have an excellent knowledge of stocks there is no dought on it, But when he asked me for a cost of application I divide application into three parts. Mobile, Admin Panel and Backend API. So what’s next surprisingly client ask why you are charging for Admin Panel and Backend API I just need a Five Screen Mobile application.

You might have heard about “A picture is worth a thousand words”. I forward following photo to client.


I request client for a Google Meet call, Because Client was genuinely interested and eager to know more about it he accepts my request. Over a call I use a restaurant and waiter example for explaining usage of API and admin panel. For client’s concept System, API and Database is Bridge between His Handpicked stock and Mobile application. Admin panel will serve as tool for daily choosing a stock for his valuable client and API will help it to show it on Clients mobile screen.

I hope by above example its clear why you need an API.

Now let’s see what are the types and Usage of APIs

Operating Systems API

At least once you have capture a photo from your mobile phone, If Not than please do it now. Because you are going to use Operating System API for it. When any Application wants to use an underlying feature of System its relay on sets of API that’s is created by Operating System Developer. This way application developer don’t need any kind of knowledge of how operating system works internally, they just need to pass sets of command and System takes care it by self.

Remote API

Remote API allows developer to access and manipulate remote resources using a protocol. Regardless of specific standard it allow different technologies to use a common resources. If we takes such standard API example than Java Database Connectivity API allows to access many different types of databases with the same set of function.


Web API is most interchangeably use with Backend API or just API. Web API access services from Client Device (Laptop, Mobile phone, etc.) to Web server. Let’s understand it’s by a picture.


Client make an API call for accessing some data to server, requesting to perform some operation or giving some data to server for storing and making calculations.

Generally Web API is calling over HTTP or HTTPS protocol.

What is REST API and SOAP API?

You might have heard about a JSON (JavaScript Object Notation) and XML (Extensible Markup Language). If Not than no issues let’s check and understand it here briefly.

Let’s see how User data object looks like in JSON and XML.


                                    "Name":"John Millar",



JSON and XML is format of data that is used to send and retrieve from server.

REST API using JSON format and SOAP API using a XML format for sending and retrieving data from server.

REST APIstands for Representational State Transfer. REST API is operate over HTTP protocol with four different Method for CURD operation. CURD stands for CREATE, UPDATE, READ and DELETE.

CREATE operation carry out by POST. UPDATE by PUT, READ By GET and DELETE by DELETE method.

SOAP API stands for Simple Object Access Protocol, SOAP is official protocol maintain by WWW (World Wide Web). SOAP API is more secure and bit complex than a REST API. It has extra overhead and data than REST API.


Intention of this blog was just to give brief introduction for:

  • What is an API?
  • What are the application of API?
  • Why you need an API and how it makes your work easy?
  • What are different types of API?
  • What is REST and SOAP API?

If it’s not enough you need some more detail and Need to develop an API Contact Us Now.