React Introduction

React was developed by the Facebook Software Engineer Jordan Walke. React is also known as React.js or ReactJS. React is a tool for building UI components.

React creates a VIRTUAL DOM in memory. Instead of manipulating the browser's DOM directly, React creates a virtual DOM in memory, where it does all the necessary manipulating, before making the changes in the browser DOM. React only changes what needs to be changed! React finds out what changes have been made, and changes only what needs to be changed. You will learn the various aspects of how React does this in the rest of this tutorial.