Why React? One of the top reasons people cite as a reason to use React is actually controversial: JSX allows you to mix JavaScript and HTML in a single component, which is transformed into pure ...

It doesn’t get too happy when you simply refer to code you’ve written for it using a script tag. React is annoyingly special that way, and it has to do with how React apps are built.

React is a JavaScript library that's used to build user interfaces, or how a user interacts with an application. Originally, a Facebook engineer built React as an internal project to manage its ads.