A React application renders an SVG circle that follows the mouse cursor across a 960 by 500 canvas. The component tracks pointer movement via the `onMouseMove` event and updates its state with the current client coordinates. React 16.9 manages the circle's position through the `useState` and `useCallback` hooks, re-rendering the SVG element as the pointer moves. The example demonstrates state-driven interactivity without a data source, relying solely on user input to drive the visualization.