A circle follows the mouse cursor across an SVG canvas, updating its position in real time to mirror the user’s pointer movements. The visualization uses React’s `useState` and `useCallback` hooks to manage the cursor’s coordinates, captured through the `onMouseMove` event on the `<svg>` element. The circle is rendered via ReactDOM, with its center tied to the `clientX` and `clientY` values from the event, demonstrating a straightforward state-driven interactive graphic.