what is createElement in react code example

Example 1: react.createElement

//Below I use the React.createElement() function to create a virtual DOM
//representation of a <li> element node containing a text node of one (a.k.a.,
//React text) and an id of li1.

var reactNodeLi = React.createElement('li', {id:'li1'}, 'one');

Example 2: React.createElement

const e = React.createElement;

ReactDOM.render(
  e('div', null, 'Hello World'),
  document.getElementById('root')
);

Example 3: react createelement

class Greeting extends React.Component {
  render() {
    return <h1>Hello, {this.props.name}</h1>;
  }
}