const element = (
  <div>
    <h1>Hello!</h1>
    <h2>Good to see you here.</h2>
  </div>
);

 Note

• JSX prevents Injection attacks. React DOM escapes any values embedded in JSX before rendering. This prevents XSS(cross site scripting attacks).
• Babel compiles JSX down to React.createElement() calls.

const element = (
  <h1 className="greeting">
    Hello, world!
  </h1>
);

const element = {
  type: 'h1',
  props: {
    className: 'greeting',
    children: 'Hello, world!'
  }
};