Ultimate Guide to React

Table of contents

What is React?
React Architecture
React Native
React's Language
JSX and Virtual DOM
Why you should use React?
What can you do with React?
React Tools
React Resources

Are you interested in using React for a web development project? Would you just like to know its benefits? Or are you just completely lost when it comes to this incredible tool? Well, if you answered yes to any of these questions, you’ve come to the right place.

In this article, we’ll go over both React and React Native, why you should use the React framework and when, as well as all the available tools and resources. Are you ready to dive in?

What is React?

Although a lot of people refer to React as a framework, the truth is, it’s actually a front-end JavaScript library. This library—also known as ReactJS or React.JS—is open-source and used to build user interfaces (UIs) for the web.

It was originally created by Facebook for internal use back in 2011 and released into the world in 2013. Today, React is an incredibly popular tool for development companies of all sizes, including Fortune 500 companies, and it’s currently on its 17.0.2 version (with version 18 looming around the corner).

The main features of React are that it’s declarative, simple, supports the server-side, it’s fast and easy to learn, and is also component-based. What are components, you ask? Well, we’ll delve into this part of the React architecture next.


React Architecture

What are components?

React divides the user interface into pieces called “components”. In this context, a component is an independent and reusable bit of code that represents part of a web page. In order to build a page with React, you need to call each component —each of which is basically a JavaScript function— in a particular order so that the user can see it.

There are two different types of components: function components and class components. Function components, also known as Stateless components, are plain JavaScript functions that return React elements. These are the ones responsible for rendering the user interface. Class components are simple classes made up of multiple functions that add functionality to your app.

We highlight components here as they make extremely easy to break down an app and are also extremely helpful when adding or changing UI details or functionalities in the app later on.

⚛ What is React Native?

As we’ve mentioned, React is often confused for a framework even though it is actually a library. Sometimes, React and React Native also get a little mixed up, which is why we’ll address both of these issues in this section.

React Native is an open-source framework—which is probably where some of the confusion stems from—, built on top of ReactJS and released in 2015. It was created by Meta Platforms, Inc., Facebook’s parent organization. Its development is currently mostly in the hands of Facebook, as well as the development community.

React Native is particularly used to develop native mobile apps. The fact that it’s cross-platform means you can use it for both iOS and Android. Other benefits of the framework include faster development, being able to create a native interface, and easy testing.

You can find out more about React Native on its website.


What language does React use?

As we’ve mentioned before, React runs on JavaScript. So what is JavaScript? Well, JavaScript is a programming language that is used to create front-end and back-end web applications.

JavaScript—often abbreviated as JS—first appeared back in 1995 and is currently the third most popular programming language, just behind Java and Python.

JSX and Virtual DOM

We’ve now covered React’s programming language, but there’s more to React development than just that.

Websites are built with HTML documents, which are read by web browsers and create a Document Object Model (DOM) in the process. This is basically a representation of how the web page will be arranged. This is where JSX, a syntax extension of JavaScript, comes in. This little critter makes it easy for developers to modify the DOM to build dynamic content for the web. In addition to being very convenient, JSX also improves performance and efficiency.

But that’s not all there is to it. Using JSX helps React create something referred to as a Virtual DOM. This is a copy of the site’s actual DOM that allows React to update the real DOM just with recent changes instead of going over the whole DOM each time there’s a small addition or change to the site.

We hope this all makes sense, but if you still have some questions, you can check React’s site for a more comprehensive explanation.


You might also like: Comparing Angular, React and Vue.JS

Why use React for Web Development?


One of the main benefits of React is its flexibility. Since it’s a library and not a framework, it can be used on a variety of different platforms. Moreover, React technology has grown and expanded over the years so it can be used beyond building static websites (with tools such as Gatsby as we’ll see below).

Furthermore, React Native can lead you into the world of mobile apps and there’s also Electron if you are after desktop applications. But that’s not all, you can use React with Next.JS for server rendering or with React VR to create virtual reality websites and 360 experiences.

Reusable Components

The fact that React is component-based is a major advantage. Since they are independent of each other, you can easily reuse them on different pages or projects. This saves you both time and money.

As React is open-source and has the large community we’ll see below, reusable components are particularly convenient. Many developers and companies share the components they built to benefit the entire community.


React is backed by Facebook, which means there are plenty of resources available around it. It is actually used in the Facebook app and website, as well as in Instagram. The top 4 contributors for React in GitHub are Facebook employees and the social media platform has racked up around 50,000 components!

React also has a blog, which is constantly updated with details of each new release (Good news! Version 18 is also underway, currently in its alpha version). The website also includes handy tutorials and links to the greater React community that we’ll discuss below.


Being a popular library, React has accrued a rather large community of collaborators and its GitHub repository rests among the Top 5. React is also used by thousands of companies such as Netflix, Airbnb and Amazon.

You can reach the React community through Reactiflux —made exclusively for React developers and exploring all related tools— and the very popular StackOverflow which includes over a quarter-million questions about the library.There is also a React community in Hashnode and another one in Reddit.

All of this means you not only have countless resources at hand, but you have even more people willing to help you out with any issues you may come across during your React development adventures.

Excellent Performance

As you may know, using DOM makes JavaScript slower than we would like. That is why React reduces DOM changes to improve performance by using a Virtual DOM and JSX as we’ve seen above.

Excellent Developer Experience

Developers react very well to React (no pun intended). Its API is easy to learn as it has very few new concepts to adopt, and the library deals with pure JavaScript and HTML making it very simple to work with.

Easy to Test

React testing is user-friendly, requiring very little configuration (or even none at all). It also uses command-line testing, which makes the process faster and more productive.

Moreover, there are many testing tools available for React. These include Jest and Enzyme for writing tests, as well as web testing frameworks such as Jasmine, AVA and Tape.


Our first definition of React mentioned UI design but the truth is that this library has expanded way beyond that. There are currently many extensions—such as React Development Tools—available that provide full architecture support making it quite a comprehensive tool.


When to use React

React’s main job is building user interfaces for single-page applications, but the story doesn’t really end there. So when should you use React? Here are our top six uses:

01. Single-page Apps (SPAs)

A single-page application is an app that works within a browser and doesn’t require the user to reload it during use. This is probably the most popular use for the React library. Some examples include Gmail, Trello and GitHub.

02. Blogs

Another use of React is to build personal or professional blogs. You can do this easily with the help of Gatsby, a static site generator powered by React. Gatsby also includes features from GraphQL, Webpack and React Router, and includes various plugins such as WordPress and Contentful..

03. eCommerce

eCommerce and retails sites are quite popular these days and React is a great tool to build them. The library helps developers implement APIs, complex filters, elements, and other features by building separate components.

04. Messaging Apps

Facebook Messenger and WhatsApp are great examples of messaging apps built using React. For this purpose, React acts as a WebSocket client and helps you maintain two-way communication between client and server.

05. Social networks

Social networks are often built as single-page applications to make dynamic updates easier. Facebook used to be a plain website but has progressed to become an SPA and added a lot of features in the process. Social network apps based on React have the benefit of rapid development and an improved user experience.

06. Cross-Platform Mobile Apps

We’ve mentioned React Native before so this comes as no surprise. The React library and the React Native framework work together to create amazing native-feel mobile apps for both iOS and Android. You can even take the web version of your app and turn it into a mobile one quite easily. Although there is no code reusability, being able to use the same architecture and methodology is definitely a great perk.


React Tools

React Developer Tools

If you are somewhat familiar with React, you probably already heard about this one. React Developer Tools is an open-source React extension for Firefox and Chrome that helps you examine the React tree (including state, props and component hierarchy).

This React tool is great for debugging components. It also includes interaction tracking, full support for React hooks and filter mechanisms.

React Sight

React Sight helps you see your React app in a flow chart structure. This platform is lightweight and unconstructive, and also works well with all libraries such as Redux and React Router. Other benefits of React Sight include the fact that it’s open-source, enhances speed and doesn’t need any setup.


Bit gives us a CLI tool as well as an online platform to publish and share React components. You can also search for components uploaded by others. This tool means you can easily reuse individual components as well as take advantage of components created by your peers.

Bit features include making your component discoverable, easy extension and integration and being language agnostic.


Storybook is the perfect tool to achieve fast iteration and testing for UI components. This open-source tool brings you much more than just code. With Storybook, you are able to develop, inspect and showcase your creations interactively, which is particularly helpful for visual components.

Storybook is easy and fast to set up and configure, allows you to build UIs in isolation and includes add-ons to build your UI even faster.


Reactitude brands itself as the “first dedicated IDE [Integrated Development Environment] for React web application development. It is actually a cross-platform desktop app that includes a custom browser simulator, an integrated Node server and visual editing support.

Its features include component visualization, streamlined configuration and hot module reloading.

React Resources

With Facebook and a large community of developers and top-notch companies behind it, React has no shortage of easily-available resources. We’ll cover some of these below to get you started.

Existing Components

Instead of building components that others have already built, you can devote your time to new features by taking advantage of existing ones. Here’s a handful of places where you can find them:

  • The Fluent UI component library, which was created by Microsoft.
  • React-Bootstrap, which makes it easy to work with Bootstrap.
  • The Rebass library, which includes primitive UI components built with a Style-System.
  • Material-UI, which is quite convenient to implement Google’s Material UI guidelines.
  • Awesome React Components, which is a list of React components available on GitHub.

Other Projects and Libraries

We could spend hours sharing more resources with you, but we’ve chosen just a few more resources we think you might like. So here are some other libraries and projects that can be used with React.

  • React Router is a library used for routing in React.
  • Redux and Reflux are libraries that can be used to manage complex data systems
  • Mobx is a state management tool that prevents state inconsistencies.
  • Jest is an excellent tool for automated React testing.
  • Express.JS is used to render components on the server-side with Node.


It’s safe to say the React library is one of the most popular development tools out there. Over the years, it hasn’t just grown its community but diversified to cover any need developers may have. It comes as no surprise that people often refer to it as a framework since restricting it to just a JavaScript library does not seem to be fair. This powerhouse has managed to create a whole ecosystem around it that allows it to reach every inch of the development world and we certainly hope you agree.

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