Application Programming Interface, commonly known as ‘API’ is a software intermediary allowing different applications to communicate with each other. In simple words, APIs are the messengers that are programmed to deliver the request from one software to the other and then pass the response back to the requesting software.
An API describes the functionalities that are independent of their implementations, that is allowing the respective implementations and keys to differ without compromising. Hence, an API provides ease in developing a program by implementing the building blocks.
Developers are more productive and efficient now with the libraries and ready-made functions rather than writing lengthy code for adding functionality to the application. APIs help the developers in using the functionality rather than reinventing the wheel every time.
When the developers create code, they don’t often start from scratch. APIs enable developers to make repeated yet complex processes that are reusable with a small code. The speed of development increases to a greater extent and the programmers can concentrate on the modern proposition of the software applications.
As defined above APIs are the link of communication between two software, take an example of a waiter in a restaurant and you are the customer who sits at the table with a menu and the kitchen wh fulfill your order. In this example, you are one application and kitchen is the other, your order from the menu will the request of data or service from the available facilities and the waiter is the API taking your order to the kitchen and after preparation delivering it to you. So the APIs are performing the function of getting a request and delivering it after being prepared from another application.
There are various kinds of APIs like Java APIs which is the interface within the classes that allows the objects to communicate with each other in the Java programming language. Then there are web APIs that are program-centric approaches such as the Remote Procedure Call (RPC), Simple Object Access Protocol (SOAP), and the most famous amongst them is Representational State Transfer (REST). According to research, there are more than 15,000 APIs that are publicly available to Programmable Web and many more private APIs used by the companies to expand their external and internal capabilities.
QL stands for the Query Language and GraphQL is a simple Query language for APIs that fulfill the queries at runtime with the existing date.
GraphQL was developed by Facebook, it is an open-source Query Language for APIs maintained by a huge community of individuals, agencies, and companies coming together from around the globe.
The responsibility of an API is to provide an interface to the data that meets the needs of the applications. It is mainly used for loading data from Server to the client-side. It does the data communication in a very efficient way rather than the traditional communication methods adopted by APIs.
The powerful tools that form the phenomena from the real world are known as Graphs as they relate to natural business models and oral descriptions of the process. The business domain is modeled as a Graph by the schema in GraphQL, within your designed schema, you set different kinds of nodes and the logic of their connection with one another.
On the frontend or the client-side, it creates a pattern related to OOP (Object-Oriented Programming). While on the other hand the server, only defines the interface, you have the freedom to use it with any backend (new or legacy!).
Basically, GraphQL is enabling the declarative fetching of data where a customer can define exactly what data it requires from an API. Rather than using multiple endpoints that deliver fixed data structures, a GraphQL server only presents a single endpoint and returns precisely the data a client requested.
GraphQL is not bound by any specified database, it is instead backed by the existing code and data of the software application. This service has been designed by defining types and building the fields on the defined types and then providing certain functions for each of the fields defined under each type.
Understanding the difference between both REST and GrahQL in APIs you must know what is REST APIs. Although REST is the most popular and traditional way to expose the data from a server.
When it was developed, the client applications were comparatively simple and hence REST was a good fit for many applications. But today the landscape of API has radically changed over the last few years.
But you must remember that GraphQL and REST APIs are two different things wherein GraphQL is a technology and a programming language, while on the other hand REST is an architecture pattern. That also means that even if GraphQL is increasingly adopted REST will still carry on in the future.
The Question arises if REST APIs were doing their job well, why was GraphQL developed by the big companies like Facebook, Coursera, and Netflix. We came up with two key reasons behind developing an alternative to REST APIs;
In Jamstack technology, the application and the website have the major factor that makes it different from the other application and brings speed, security, and scalability to the web app.
Take an example of building a website using Jamstack technology, so it will have a Static Site Generator like Gatsby or RestJS, a headless CMS like WordPress or Contentful and APIs will be the communication hub between these two platforms. Herein the static site generators like GatsbyJS have a mechanism for getting the data onto the page through the build process by performing the page queries. So to execute a page query, you need to export a GraphQL query from the page component.