Classes

React.Component is the base class for React components when they are defined using ES 2015 classes

React.PureComponent is similar to React.Component. The difference between them is that React.Component doesn't implement shouldComponentUpdate(), but React.PureComponent implements it with a shallow prop and state comparison.
If your React component's render() function renders the same result given the same props and state, you can use React.PureComponent for a performance boost in some cases.

import React from 'react';  
 
class Hello extends React.Component { 
  render() { 
    return ( 
        <div> 
            <h1>Hello</h1> 
        </div> 
    ) 
  } 
}