A circle follows the mouse cursor across an SVG canvas. The visualization uses React's `useState` hook to track the cursor's current coordinates, updating the circle's `cx` and `cy` attributes on every mouse move event. The React component renders the SVG directly, with the circle's position bound to the state value. The canvas is set to a fixed width and height, and the mouse position is captured via the SVG's `onMouseMove` handler. Both React and ReactDOM are loaded from UMD packages.