A circle within an SVG canvas follows the mouse cursor in real time. The visualization uses React’s `useState` to track the cursor’s `clientX` and `clientY` coordinates, updating the circle’s center position on every `onMouseMove` event. The component renders a static 960×500 pixel SVG, with the circle’s radius fixed at 30 pixels. The code imports React and ReactDOM, and the initial mouse position is set to the canvas center before any user interaction.