This example demonstrates a minimal React setup where the message "Hello React!" is rendered directly into the page. The code imports React and ReactDOM, defines a simple functional component named `App`, and mounts it to the `#root` element using `ReactDOM.render`. It relies on the production builds of React 16.9.0 loaded via CDN, with the main application logic contained in a separate bundled JavaScript file. No data visualization or external libraries are used beyond the core React framework.