React is an open source Javascript library used to make dynamic User Interfaces. You can think of it as the View in MVC.
Strictly speaking, there’s no strictness with React. You can use it with most of the JS libraries out there.
Made by Facebook and Instagram, it’s now used by most of the leading tech companies around world. Some of them, other than Fb and Insta themselves are:
React is giving a tough competition to it’s rivals Angular and Ember (Though each of them are releasing new versions with more features.)
It’s definitely worth giving React a try.
Check out https://facebook.github.io/react for understanding how React works.
Aditya Rohilla 