A yellow circle follows the mouse cursor across a 960-by-500 SVG canvas. The example demonstrates React’s state management and event handling: the `App` component tracks mouse coordinates via `useState` and updates the circle’s `cx` and `cy` attributes on every `onMouseMove` event. It renders through `ReactDOM.render` into an HTML `#root` element, with the SVG output generated entirely by React elements rather than a separate charting library.