ReactJS is one of the most popular JavaScript front-end libraries which has a strong foundation and a large community.
ReactJS is a declarative, efficient, and flexible JavaScript library for building reusable UI components. It is an open-source, component-based front-end library that is responsible only for the view layer of the application.
ReactJS is an open-source JavaScript library used to build a user interface for Single Page Application. It is responsible only for the view layer of the application. It allows developers to compose complex UIs from a small and isolated piece of code called "components."
ReactJS is made of two parts: First is components, that are the pieces that contain HTML code and what you want to see in the user interface, and the Second one is HTML document where all your components will be rendered.