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What is API?

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In this tutorial, we will learn about the API. We will cover the following terms related to API.

  • What is API?
  • Example of API
  • API how it works?
  • Types of API
  • Why is API needed?
  • Features of API
  • Web API
  • API Application

What is API?

API or Application Programming Interface is an interface through which two or more applications can interact using several functions.

Data can be transferred with each other without any intervention between the applications. 

It is a collection of software procedures and functions designed to allow two different applications or software to interconnect and then exchange or transfer data with each other when executed.

There are multiple applications of API owing to its basic functionality. The software code allows different services to communicate with each other effectively without them knowing how the whole thing is being implemented and executed in the background.

Example of an API

An API act as the messager between the application or software and the user.

The API has some data and performs actions whenever called.

API – how does it work?

API functionality and working are simple to understand. One good example of how API works is when you are getting tickets for a game. You just have to put in the relevant information like which game you are going to, your name, credit card info, etc., and the system will generate or print out your tickets.

Another example would be to get tickets for a movie or a show. You input your information and voila, your tickets are printed out.

A great example of APIs is the availability of Google Maps services on different ride-ordering apps like Uber. You can easily locate your destination on the app thanks to its info sharing with Google Maps.

All of this seamless transfer of information is thanks to API. It allows the different software on the website or the movie theater’s computer to exchange information with other software to verify and complete the transaction seamlessly, without you even knowing.

API types

APIs can be classified into four main types

Public APIs

Public API or Open API is the type of interface that is publicly available for developers to use without any restrictions. A good example is the OAuth APIs from Google. Other examples include Microsoft Windows API, Apple’s Cocoa and Carbon APIs, etc.

Internal APIs

These APIs are developed specifically for use within a company or a business. The APIs are private and custom-built keeping the requirement and services of the company in mind.

Partner APIs

These APIs are not available publicly and require a license to be accessed and used.

Composite APIs

As the name indicates, it is a type of API that combines service and data exchange APIs.

Why is API needed?

API is a versatile software code and can be helpful due to the following reasons.

  • API (or Application Programming Interface) helps two different applications or software to communicate and trade data among each other effectively.
  • The interface is helpful in efficiently embedding or inserting content from different websites, applications, and software.
  • The interface is helpful for businesses and companies that they can easily customize the services and products for their used.
  • APIs make the service and information delivery flexible and easy as it can easily access different app components.
  • For web developers and managers, content publishing is made easy as it can be done automatically.
  • The interface code can also anticipate and predict any updates that might be required for the software for its proper functioning.

Features of API

API offers tons of useful following features:

  • The interface offers a wide range of services to the users like data exchange, inter-software communication, etc.
  • It can help out in creating a good business model for your services.
  • The interface is very flexible and adaptable thanks to its simplicity.
  • API provides great developer support for example in the web development industry.

API’s communication levels

APIs can be divided into two basic categories according to their communication levels.

Low-Level APIs are designed to be more detailed in their design and functionality. In this case, the programmers have a limited level of abstraction. This allows the coder to manipulate and change the functions of the application and software when required.

High-Level APIs are designed to be used in REST form with programmers having a high level of abstraction compared to Low-Level APIs. These interfaces are designed for limited functionality.

Web APIs

A Web Application Programming Interface or Web API for short is designed to use for a web browser or a server. These APIs are divided into two main types:

Server-side API

Server-side API is usually expressed in XML or JSON. It is designed in a way that it has exposed endpoints to a request-response message system allowing access to data and endpoints to manipulate that data.

Client-side API: This type of Web API allows the enhancement of functionality within an HTTP client or a web browser.

Some examples of web APIs include Google Maps APIs (which allow embedding Google Maps in applications and websites), YouTube APIs (which allow integrating YouTube videos into websites), and APIs for Twitter, Instagram, Facebook, Amazon, etc.

API Applications

Thanks to its versatility and functionality, API has multiple applications. Some of which are as follows:

  • Developing features
  • Expanding the footprint of services
  • Batch distribution
  • Driving traffic to a site
  • Exploring new and improved business models
  • Distribution of contents internally
  • Innovation and advancement in services
  • Allowing programmers to manipulate resources remotely