A React component renders an SVG circle that follows the mouse cursor across a 960x500 viewport. The application uses React's `useState` hook to track the cursor's `clientX` and `clientY` coordinates, updated by an `onMouseMove` event handler on the SVG element. The circle's `cx` and `cy` attributes bind to the stored position, creating a direct visual response to pointer movement. The visualization demonstrates a simple, interactive SVG rendering approach using React 18 and ReactDOM.