React is a popular Javascript library that you may have heard of mentioned along side of other frameworks such as Angular and Vue. I would say that it's appeal that it is more like writing Vanilla Javascript rather than learning a complex framework such as Angular. Of course, most React apps are accompanied by Redux, a predictable state container that uses the FLUX pattern of actions passed through a single dispatcher in order to control the state of the application. Together Redux and React combine to provide a light weight and stable framework for building applications. Being supported by Facebook makes it a creditable solution in app development until something new comes along. 

If you compare the weekly downloads of react vs @angular/core, you may determine that React has become more standard in JS app development. So you may want to go with React if starting a new application, so that you will be able to hire the best and brightest young devs to build your business.