3.1 What is React?

React is an open-source project, heavily sponsored by Facebook. It is the most popular modern JavaScript library for building user interfaces. It provides a declarative framework for building data-driven user interfaces and efficiently manages updating the DOM with just the components that have changed; minimizing full-page re-paints.

React provides the foundation for and strongly encourages the use of best-practice software application design patterns.

Over the next few exercises, you will learn some of the basic concepts of React and how it relates to what you already know. We will take a software development journey from Vanilla JS to JSX.