What is React ?
ReactJS is a JavaScript library used to build interactive user interfaces (UIs) and single-page applications (SPAs). It was created by Meta (formerly Facebook) and is maintained by a large open-source community.
React allows developers to create component-based architecture, enabling fast, scalable, and maintainable web applications.
Why Learn ReactJS
Used by top companies like Facebook, Netflix, Uber, and Airbnb
In-demand skill for web developers
Massive ecosystem and job opportunities
Powerful tools like React Router, Redux, Next.js, and React Native
What You Need to Start with ReactJS
Before diving into React, make sure the following tools and knowledge are in place:
Prerequisites:
Basic knowledge of:
HTML
CSS
JavaScript ES6+ (arrow functions, destructuring,
let/const, modules)
Installed software:
Node.js and npm – https://nodejs.org
Code editor – Visual Studio Code
Browser – Google Chrome or Firefox
Top Features of ReactJS
| Feature | Description |
|---|---|
| ⚛️ Component-Based | UI is broken into small, reusable pieces called components |
| ⚡ Virtual DOM | Faster updates using an in-memory DOM system |
| 🔁 Unidirectional Data Flow | Data flows in one direction, making debugging easier |
| 🧩 JSX Syntax | JavaScript + HTML-like syntax for UI templating |
| 🔄 Hooks | Simplify logic and state in functional components (e.g., useState, useEffect) |
| ♻️ Reusable Code | Components can be reused across pages and projects |
| 🌐 Strong Community | Thousands of libraries and learning resources available |
Top Companies Using ReactJS
| Company | Use Case |
|---|---|
| React was created for Facebook’s UI | |
| Built entirely using React | |
| Netflix | Fast loading experience using React |
| Airbnb | React components power its booking interface |
| Uber | Dashboard and maps use React for real-time UI |
| Shopify | Uses React for frontend commerce interfaces |