1:what is the purpose of react router?

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.

2:how does context api works?

Context API is used to pass global variables anywhere in the code. It helps when there is a need for sharing state between a lot of nested components. It is light in weight and easier to use, to create a context just need to call React.createContext ().

3:what is use ref in react?

useRef () is a built-in React hook. This hook accepts one argument as the initial value and returns a reference (known as ref). The reference is the object having a special property current.