React Router is a standard library for routing in React. It enables the navigation among views of various components in a React Application, allows changing the browser URL, and keeps the UI in sync with the URL. It is used basically for SPA or single page application. Where the page dont refresh by time. It reloads at only first moment and then shows the routes.

The React Context API is a way for a React app to effectively produce global variables that can be passed around. This is the alternative to "prop drilling" or moving props from grandparent to child to parent, and so on. Without drilling props in multiple layers. Just dynamically call the context and you will get the data.

The useRef is a hook that allows to directly create a reference to the DOM element in the functional component. Syntax: const refContainer = useRef(initialValue); The useRef returns a mutable ref object.