An interactive React application renders an SVG circle that follows the mouse cursor. The code tracks pointer position through an SVG `onMouseMove` event handler, updating React state via the `useState` and `useCallback` hooks to reposition the circle. Rendering uses React 16.9 and ReactDOM, with the circle initially centered at 480,250 on a 960x500 canvas. No external charting libraries are used; the visualization relies purely on declarative JSX and SVG elements to demonstrate reactive mouse tracking.