React is a JavaScript library for building user interfaces.

There are two key things to know about React. It is declarative and knows only to update what is changed in the DOM. It is flexible as it works with libraries and frameworks you already know (e.g. it works with Rails).

Reacts representation of DOM is an XML-like syntax called JSX. This JSX makes the code more readable and writing it feels like HTML.

These are reasons why React should be used:

  • It works great for teams, strongly enforcing UI and workflow patterns
  • UI code is readable and maintainable
  • Componentized UI is the future of web development, and you need to start doing it now