This example displays a large, centered "Hello React!" message on a plain web page. It renders the text by defining a React component and mounting it to a root `<div>` element using the `ReactDOM.render` method. The implementation imports React and ReactDOM from the `react` and `react-dom` packages, and includes a simple console log statement for debugging. The page loads React through CDN links, and the component’s styling comes from a CSS class setting the font size to 13em.