React: What is React DOM updates?

Update process:

1. Trigger: setState, prop change, parent re-render
2. Render: call component function
3. Diff: compare virtual DOM
4. Commit: apply minimal DOM changes
5. Effects: run useLayoutEffect, useEffect

1function Counter() {
2  const [count, setCount] = useState(0);
3  // Trigger: setCount
4  // Render: Counter() called again
5  // Diff: count changed
6  // Commit: update text node
7  return <div>{count}</div>;
8}

Batching: Multiple updates in one render, automatic in React 18+.

Priority: Transitions are low priority; regular updates are high priority.