React is a very popular framework today, and rightfully so. Once you are comfortable with it, the experience of writing a web application becomes downright enjoyable. The community of React developers is vibrant. The pace of change in the framework is fast (maybe a little too fast at times) but well supported by Facebook and the open source community. Most importantly, it allows you to focus on simple pieces of functionality that can easily be composed and reused throughout your application.
React or React JS is a JavaScript front-end library from Facebook which lets you create HTML based GUI. It makes the task easier by providing a component-based architecture which was only available to languages like Java and C# before.
Because of this awesome feature, React is quickly becoming the standard JavaScript library for developing front-end. That’s the reason many programmers and developers are learning React or React JS.