React: What is React 19 ref forwarding?

1const TextInput = forwardRef((props, ref) => (
2  <input ref={ref} {...props} />
3));

1function TextInput({ ref, ...props }) {
2  return <input ref={ref} {...props} />;
3}

1function FancyInput({ ref, ...props }) {
2  const inputRef = useRef(null);
3
4  useImperativeHandle(ref, () => ({
5    focus: () => inputRef.current?.focus(),
6    clear: () => {
7      if (inputRef.current) inputRef.current.value = "";
8    },
9  }));
10
11  return <input ref={inputRef} {...props} />;
12}