A React Hooks demonstration shows a grid of apple emoji whose count starts at 24 and adjusts with plus/minus buttons. The `Tree` component uses `React.useReducer` to manage the count state, while `React.useEffect` tracks mounting and updates a status message. Each apple renders through a separate `Apple` component that sets a message via `React.useState`. The code uses React 16.10 UMD builds and plain CSS for button styling, with the interactive behavior centered on toggling the reducer actions.