React: What is React form handling?

1function LoginForm() {
2  const [email, setEmail] = useState("");
3  const [password, setPassword] = useState("");
4  const handleSubmit = (e) => {
5    e.preventDefault();
6    login(email, password);
7  };
8  return (
9    <form onSubmit={handleSubmit}>
10      <input value={email} onChange={e => setEmail(e.target.value)} />
11      <input type="password" value={password} onChange={e => setPassword(e.target.value)} />
12      <button type="submit">Login</button>
13    </form>
14  );
15}

1function LoginForm() {
2  const emailRef = useRef();
3  const handleSubmit = (e) => {
4    e.preventDefault();
5    login(emailRef.current.value);
6  };
7  return (
8    <form onSubmit={handleSubmit}>
9      <input ref={emailRef} defaultValue="" />
10      <button type="submit">Login</button>
11    </form>
12  );
13}