React JS Intro (Image by - Sharma Guides | Subham232330) What is ReactJS? * ReactJS is a free and open-source JavaScript library for building user interfaces using a component-based concept. * ReactJS is also known as React, React Js. * React is maintained by Facebook. * ReactJS is not a framework, it is a library. Examples of ReactJS websites:- Facebook, Discord, Netflix, Dropbox Advantages of ReactJS 1. DOM Virtuality 2. Easy Testing 3. SEO Friendly 4. Blazing Fast 5. Efficient Debugging Prerequisites HTML CSS JavaScript ES6:- let, const, arrow function, classes, object literals, spread operators.