what is the purpose of props in react code example

Example 1: props in react

function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

function App() {
  return (
    <div>
      <Welcome name="Sara" />      <Welcome name="Cahal" />      <Welcome name="Edite" />    </div>
  );
}

ReactDOM.render(
  <App />,
  document.getElementById('root')
);

Example 2: props in react app

/* PASSING THE PROPS to the 'Greeting' component */
const expression = 'Happy';
<Greeting statement='Hello' expression={expression}/> // statement and expression are the props (ie. arguments) we are passing to Greeting component

/* USING THE PROPS in the child component */
class Greeting extends Component {
  render() {
    return <h1>{this.props.statement} I am feeling {this.props.expression} today!</h1>;
  }
}

--------------------------------------------
function Welcome(props) {
  return <h1>Hello, {props.name}</h1>;
}

const element = <Welcome name="Sara" />;
ReactDOM.render(
  element,
  document.getElementById('root')
);