React allows you to build stateful javascript components in a nice manner. Think change propagation. You have a visual tree of a parent component and many child

React allows you to build stateful javascript components in a nice manner. Think change propagation. You have a visual tree of a parent component and many child components. React makes it really nice, easy, and fast to propagate changes up and down your visual tree. Very MVVM-like, to me. You change some state, and React takes care of updating the appropriate visual components. This is achieved with some custom syntax and also a fake/virtual DOM that you work with. The gain from all this is speed. It's impressively fast, in fact.