Application Programming Interface Introduction.
Welcome to today’s article on “Application Programming Interface (API)”. You’ll learn the basic concept and the complete life cycle of APIs. in addition, you will also get the basic overview of web API, microservice, REST API, SOAP API, APIs category and how APIs works. Let’s begin our tutorial with an overview of application programming interfaces (APIs).
Table of Contents
What is an API?
An acronym API stands for the Application Programming Interface. It’s a special class of software or a set of protocols or set of routines that enable interaction between different applications.
APIs are available on all most all platforms and support all devices. These are generally small server-side application, deployed in the form of a micro-service and can be hosted on any platform.
The application programming interface enables the interaction between the application hosted either on the same platform or on a different platform. It also enables the secure exchange of the data between different systems.
All APIs are not Web Services. However, all Web Services are termed as APIs.
APIs help in creating the decoupled and reusable building blocks that can be used in software development. The below API flow diagram highlight the basic architecture of an API.
Millions of mobile users everyday make billions of API calls to book their flight, transfer payments, book taxi, etc. and everything is possible due to APIs. API is driving the world and APIs have become an irresistible product for a business house. Here, are some example of tops used APIs in 2020:
How Application Programming Interface Works?
- Open your mobile app and type your login credentials.
- As you click on login, the mobile app use API service to initiates a session with your banking application to authenticate your credential and get the account balance.
What are key benefits of Using APIs?
- APIs are fairly simple and easy to use. Being a programmer you’re not required to build an application right from scratch. You only need to build logic to consume data return by API services.
- APIs support various data exchange format such as JSON, CSV which is fairly easy to parse by the applications.
- APIs can be used to expose legacy data to the outside world in a secure way.
- APIs can be used to automate work, in-fact they can scale the service on demand.
What are different types of API?
By now, you’ve understood the meaning of APIs and their practical use in various areas. Now, let’s concentrate on the different types of application programming interfaces (API). Generally, there are three different types of APIs category:
Ownership Based APIs
Based on the access level, APIs are further divided into Public API and Private API. Public APIs can be accessed by anyone without any restriction. However, private APIs are designed and used internally within the application or organization.
Communication Based APIs.
The next API classification is based on communication levels. These APIs are classified as high-level API in the form of REST APIs and system-level APIs in the form of SOAP APIs. System-level Apis generally support more system-level functions.
Web Service Based APIs.
The last category of APIs is web services API, these are generally used a different set of protocols and data formats. The Web services are divided into four types i.e. SOAP, JSON-RPC, XML-RPC, and REST APIs.
The below diagram showcases the different types of API category.
You might be wondering that REST APIs and WEB APIs are two different concepts. But, you will be surprised to know that both the REST API and WEB API are two sides of a coin. They are very similar in functionality and has a minor difference. Let’s go them one by one.
What is a Rest API?
The term REST stands for Representation State Transfer. It’s easy to learn and flexible to use and you don’t need any special tools. Roy Fielding developed the REST API in the year 2000.
He and his team keep the design of the REST API simple and easy to use. It was designed to overcome the shortcoming of SOAP APIs.
- GET Method – is used to retrieve the record.
- PUT Method – is used to update the record.
- POST Method – is used to insert the record.
- DELETE Method – is used to delete the record.
WHAT IS A WEB API?
A web API is a web interface for any external or internal application. In laymen terms, it’s a point where two applications meet and exchange data by using a common set of protocols.
Web APIs are generally known as remote APIs that use the HTTP protocol for communication. In the below example, the mobile application is a consumer of the API hosted on a webserver. The back-end server will act as provider because it fulfils the request of a web server.
What is a SOAP API?
What is a Microservices?
The application programming interface begins with a well thought robust design. The design should be leak-proof and follow enterprise architecture guidelines. In this stage, you prepare the resources and operational requirements along with the business case scenarios.
The next phase is the development phase. In this phase, APIs business logic is developed as per business requirements. This phase is quite important because in this phase design is transformed into code.
In the third phase in testing, in this phase, the APIs logic is tested as per business requirements. You test the API to ensure that the quality and performance of the API is robust and to avoid any hiccups in productions.
The fourth phase is to deploy the tested API into secure production environments. Then new API can be accessed via any third-party or inhouse applications.
Retiring or Deprecating Phase
The final phase of the API life cycle involves retiring or deprecating the API. In this phase, the older version of APIs is retired including support for the corresponding API.