ReactJS - Overview

ReactJS is JavaScript library used for building reusable UI components. According to React official documentation, following is the definition −
React is a library for building composable user interfaces. It encourages the creation of reusable UI components, which present data that changes over time. Lots of people use React as the V in MVC. React abstracts away the DOM from you, offering a simpler programming model and better performance. React can also render on the server using Node, and it can power native apps using React Native. React implements one-way reactive data flow, which reduces the boilerplate and is easier to reason about than traditional data binding.

React Features

• JSX − JSX is JavaScript syntax extension. It isn't necessary to use JSX in React development, but it is recommended.
• Components − React is all about components. You need to think of everything as a component. This will help you maintain the code when working on larger scale projects.
• Unidirectional data flow and Flux − React implements one-way data flow which makes it easy to reason about your app. Flux is a pattern that helps keeping your data unidirectional.
• License − React is licensed under the Facebook Inc. Documentation is licensed under CC BY 4.0.

React Advantages

• Uses virtual DOM which is a JavaScript object. This will improve apps performance, since JavaScript virtual DOM is faster than the regular DOM.
• Can be used on client and server side as well as with other frameworks.
• Component and data patterns improve readability, which helps to maintain larger apps.

React Limitations

• Covers only the view layer of the app, hence you still need to choose other technologies to get a complete tooling set for development.
• Uses inline templating and JSX, which might seem awkward to some developers.