React

// This is a Class component
class Welcome extends React.Component {
 render() {
  return <h1>Hello, {this.props.name}</h1>;
 }
}// This is a functional component
function Welcome(props) {
 return <h1>Hello, {props.name}</h1>;

reference:

https://reactjs.org/docs/react-component.html 

https://medium.com/swlh/react-basics-components-and-the-importance-of-state-dd26250e88ce 

https://medium.com/weekly-webtips/react-basics-whats-the-difference-between-javascript-and-jsx-604dd224b1cf