ReactJS Tutorial

What is ReactJS? Features, Uses, Benefits, Full Introduction

Table of Contents

  • Introduction to ReactJS
  • What is ReactJS?
  • What is React JS? How does React JS Work - Features of React Js
  • Top Features of ReactJS
  • Why Use ReactJS?
  • Pros and Cons of ReactJS
  • Applications and Uses of ReactJS
  • Top Companies and Websites Using ReactJS
  • ReactJS FAQs

Introduction to ReactJS

ReactJS is everywhere, with companies and brands, big or small, using it to build their websites and web applications. The 2021 State of Developer Ecosystem Survey revealed that 49% of developers worldwide rely on and use React. Moreover, Facebook has acquired one of the largest active user bases globally, and the company uses React for its popular social network mobile app.

Whether you are a beginner looking for detailed information on what is ReactJS or just want to brush up on your knowledge of this JS library, this article has everything you need to know.

What is ReactJS?

ReactJS is an open-source JavaScript library built and maintained by Facebook. Since its launch, React has taken the IT industry, especially front-end development, by storm. It is used to create composable user interfaces using declarative code. As stated by Jordan Walke, creator of ReactJS, React is a flexible and efficient JS library capable of rendering front-ends of simple, scalable, and fast web applications. 

It is a component-based framework that supports the creation of the application’s view layer. It follows MVC (Model View Controller) architecture, and the view layer is accountable for managing web and mobile apps. It is also a popular choice for building SPA (single-page applications). 

According to a study by Statista in 2022, React is among the most popular frameworks globally. It is named alongside NodeJS and Angular. 

What is ReactJS?

Today, more than 220,000 live websites, including BBC, Apple, Netflix, and Paypal, use React for software production.

What is React JS? How does React JS Work - Features of React Js

What is React JS? How does React JS Work - Features of React Js

Top Features of ReactJS

Here are some exclusive features of React that make it one of the most sought-after web technologies worldwide:

1. Virtual DOM

DOM (Document Object Model) is a crucial part of the web as it executes the code. Generally, the JS framework updates the entire DOM at once, slowing the web application. However, React uses virtual DOM, a lightweight representation of real DOM. 

Whenever there is a modification in a web application, VDOM is updated first, finds the difference between real and virtual DOM, and modifies the part with the recent changes while keeping everything else the same. 

This saves a significant amount of development time and cost compared to front-end technologies that update every component, even when there is a single change in the web app. 

2. JSX (JavaScript Syntax Extension)

JSX, a combination of HTML and JavaScript, is a preferred choice for many web developers. It describes the user interface appearance of an app and is used to create React components. 

JSX is one of the best ReactJS features as it makes it easier for developers to write building blocks. It is not necessary to use JSX in ReactJS development, but there is a huge difference between writing ReactJS documents in JavaScript and JSX. 

The latter is a syntax extension of the former. Using it, one can write HTML structures in the same file that has JS code. Browsers do not support JSX, so Babel compiler transcompile code into JS code. 

3. Extensions

React supports numerous extensions used for application architecture. It also supports mobile app development, server-side rendering, and Redux. Moreover, it is extended with React Native and Flux, which enable cross-platform apps and seamless UI. 

4. One-way Data Binding

One-way binding means that React uses unidirectional data flow, i.e., data is transferred in one direction, which is from top to bottom or from parent to child components. The properties in the child component can’t return data to parent components but can communicate with the latter to change the state based on provided inputs. 

This forces developers to use the callback feature to modify components rather than editing them directly. Also, it allows developers better control over apps and makes them more effective and flexible. 

5. Component-based Architecture

ReactJS divides the UI of a web page or app into multiple components, with each its own logic written in JS. So the developers can relay the data across the app without impacting the DOM.

Why Use ReactJS?

ReactJS has become a popular JS framework, and many use it to avail of the amazing benefits of ReactJS. Here are a few reasons why you should use ReactJS.

1. Short Learning Curve

Compared to other frameworks, ReactJS is easier to learn, which adds to its popularity. It allows developers to complete their projects in record time, and businesses can be up and running asap. 

The harder to learn a technology or framework, the more time it takes to begin the development process. And we tend to avoid complicated things. However, as ReactJS is easy to learn, people prefer to use it. 

2. Facilitates Creation of Custom Components

ReactJS comes with JSX, which is an optional syntax extension to make it possible to write components. They accept HTML quoting and make subcomponents rendering a great experience for developers. Moreover, after creating components, developers can reuse them, which speeds up the development process. 

3. SEO-friendly

One of the greatest benefits of ReactJS is its SEO-friendliness and its focus on rendering speed. JS-based websites can face issues because of DOM rendering and can take a long to load. However, with virtual DOM and server-side rendering, this issue is resolved as Google and other search engines don’t use JS for content rendering. 

4. Useful Developer Toolset

Learning emerging technologies and applying them in real-life projects can be fun and advantageous. But only if they are used correctly. 

Hence, Facebook added React dev tools and Chrome dev tools in ReactJS, which help developers discover child and parent components, inspect their present state and props, and observe component hierarchies. 

5. Availability of Extensions

ReactJS is rich in extensions, which make the coding environment comfortable for developers. Moreover, it makes it easier to read and understand code. For example, Chrome browser extension support is good for tracing components and the Redux store. 

6. Thriving Community

ReactJS is backed by a strong community, which can be attributed to its open-source feature. Every day, a large number of loyal ReactJS developers contribute toward making it a better framework and resolving any glitches. 

Be it a bug, technical problem, or any other query, you can seek any assistance, and the community will always be available to help you. Moreover, ReactJS experts continuously update and upload free tutorials on various platforms. 

7. Scope for Testing the Codes

ReactJS applications are easy to test, allowing developers to test and debug code using native tools. Jest is popular for testing React apps, and Enzyme is another well-known testing utility that helps developers check their code. 

Another important thing is various frameworks and libraries are available that support React structure, including API calls. Developers just need to set the testing script once, and by running the script, anyone can have an idea of the test results and trace the point of failure. Hence, making code monitoring and functional flow sophisticated and time-efficient. 

8. Cross-platform Functionalities

Another highlight of React is its spin-off framework react native, meant for cross-platform development. One astonishing benefit of React Native is that you have to write code just once for iOS and Android. 

9. Trusted by Many Fortune 500 companies

If you are still not sure about ReactJS uses, take inspiration from global giants and Fortune 500 companies, such as Tesla, Walmart, Airbnb, and Tencent QQ, that trust ReactJS and its framework React Native for their mobile apps and websites. React web framework is currently being utilized by companies such as BBC, Netflix, NASA, Lyft, New York Times, and Paypal.

10. Enhanced Code Stability

ReactJS follows a downward data flow that ensures the parent structure is not affected by any changes made in the child structure. Whenever developers have to make modifications, they only have to edit their states and make proper amendments. 

So, just a particular component will be updated while others will remain unchanged. This ensures better code stability and smooth app performance. 

11. Improved Developer Productivity

With its feature of reusable components, developers can redistribute the same digital objects. ReactJS is easier to manage for developers, even when there are frequent changes in components. They only have to add buttons, text fields, and simple elements, and place them in wrapper components and to the root element. As React component has a unique internal logic that is easy to operate, this improves the maintenance and growth of code.

Pros and Cons of ReactJS


Here’s a look at the pros and cons of ReactJS that you must be aware of:

1. Fast Rendering

Generally, you need to define the app structure at the outset when developing a high-load and complex application. However, virtual DOM provides valuable benefits, and the DOM structure is like a tree. 

Contrary to small edits at the top-level layer that can hit the UI hard, with VDOM, all changes can be initially tested to find the risk level before finalizing the modification. This enables developers to build superior UI and high-performing apps.

2. Rich UI

UI is crucial to the success and performance of any app. A poorly designed user interface can hamper the experience and reduce the app’s chances of success. On the other hand, a high-quality UI increases the chances of users’ attention and interest. This is where ReactJS comes in. It helps build a top-notch and rich UI with its declarative components. 

3. Redux

Using the Redux feature, developers can manage the state of the app. If used with other frameworks, it can prove to be a great tool for building UI. Redux forces React components to avoid interacting with or depending on each other. Components transmit data to Redux, which updates the other components. 

Hence, they remain updated with the latest data without relying on each other. This fastens the development process, and apps are more stable and can run in different environments. 

4. Handy Tools

React is known for its development tools and dependencies to assist developers. Two of them are React Developer Tools and Redux Developer Tools, which are browser extensions for Chrome and Firefox. The tools detect errors in code and fix them so developers just have to install them and start using them without any additional skills. 

5. High-compatibility

React was designed to be compatible with other JavaScript libraries without restricting the possibility of using additional tools to create a website. You can select any ReactJS extension that, with the help of outside controllers, will define the view layer of a page. It is easier to work with React on simple pages, but complex ones need more libraries to function properly. 

6. Scalability

Thanks to the modular design of ReactJS, it is easier to scale than various platforms. You simply have to add components, replace old ones with robust versions, and make application changes piecemeal to ramp up an app. 


Unfortunately, despite its numerous benefits, ReactJS has some drawbacks too:

1. Lack of adequate documentation 

Because of rapid development, documentation and resources can be sparse to cover the latest updates. New releases and updates hardly leave enough time to write and complete documents. 

ReactJS, as an open-source framework, enables developers to create their support documents. However, anyone can create these resources, which also increases the chances of poor ones that have little to offer. 

2. Only Focuses on User Interface 

ReactJS consists of a plethora of tools but they are used only to create the user interface. Hence, it is not an ‘all-in-one’ tool for app development, and you need to use other technologies and tools to create functional apps and backend parts.

3. High Pace

ReactJS is constantly changing and evolving but it can be a drawback at times. Many developers argue that ongoing changes put a lot of pressure on them to constantly learn about ReactJS, and it can be difficult for them to keep up. 

4. JSX as a Barrier

JSX is a syntax extension that allows HTML and JS to mix together. This may seem beneficial, but some consider JSX as a barrier, especially for new developers. This is a common complaint and hurdle in the learning curve. 

Applications and Uses of ReactJS

In this section, let’s discuss applications of ReactJS. It may not be a one-stop solution, but it offers plenty of uses. React is ideal for developing:

  • Interactive elements within UI

  • Stable coding

  • Fast, responsive, and efficient SPAs

  • Components for high-performing apps

  • SEO-friendy apps

  • Quick-loading web apps

  • Apps for native platforms

  • Scalable apps where you can frequently add new features

Top Companies and Websites Using ReactJS

ReactJS is trusted for creating scalable, fast, and efficient web applications. Hence, gaining immense popularity across the world. Thousands of websites and companies, from startups to large enterprises, rely on it. 

We have mentioned a few notable ones below:

  • Facebook

  • Instagram

  • Wix

  • Netflix

  • Whatsapp

  • Reddit

  • Uber

  • Dropbox

  • Airbnb

  • Skyscanner

  • The New York Times

  • Khan Academy

  • Walmart 

  • Pinterest

  • Codecademy

  • SoundCloud

  • Discord

ReactJS FAQs

1. What is ReactJS used for?

React is a popular JS library developed by Facebook and was also used for building It allows developers to create seamless and fast UI easily for their websites and apps. Moreover, its virtual DOM feature is like a tree based on JavaScript components. 

2. How to learn ReactJS?

If you want to learn ReactJS, we recommend joining a reliable ReactJS course. Seek professional guidance from experienced mentors who can even share industry insights and help you explore better opportunities. WsCube Tech is one such leading ed-tech company that offers a comprehensive MERN Stack course to aspirants. It offers hands-on projects, regular assessments, live classes, job assistance, and professional assistance that ensure impactful and valuable learning experiences.

3. Is React a framework?

React is an open-source front-end JS library used to build user interfaces based on components. There are a few debates on whether React is a framework or a library, as many use these words interchangeably. However, they are not the same. 

Frameworks meet the following criteria:

  • Provide templates and ready-to-use tools

  • Control calling of libraries for code

  • Are consistent with APIs, toolsets, compilers, and libraries within

  • Give guidelines and rules to write code and structure files

  • Controls the flow and calls of code, but libraries allow you to control the flow of applications.

Since React doesn’t meet these requirements, it is clearly a library.

4. Who developed ReactJS?

React was created by Jordan Walke, a software engineer at Meta, in 2011.


Comparing React with other frameworks can be tough, considering it’s a library. However, it is safe to say that it is well-appreciated and highly trusted for what it is. It is a great JavaScript library that is a preferred choice for many developers. Yes, many consider it overwhelming, but that doesn’t take away the fact that it is one of the top-ranked JS libraries worldwide.

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