This example shows a minimal React application that renders a centered “Hello React!” message in large text. The code imports React and ReactDOM, defines a simple functional component called `App`, and uses `ReactDOM.render` to mount it into a `#root` div. It loads React 16.13.1 from a CDN and relies on a separate `bundle.js` file for the compiled application logic. The styling is applied through a global CSS class named `.message` defined in the HTML file.