This example demonstrates the minimal setup for a React application that renders a static “Hello React!” message inside a web page. It uses the React and ReactDOM libraries loaded from a CDN, with an `index.html` file that includes the root `<div>` and a compiled `bundle.js` script. The `index.js` file defines a simple functional component and calls `ReactDOM.render` to mount it into the `#root` element, showing how to wire React’s declarative components into an HTML page.