How does async/await work under the hood?

async/await is syntactic sugar over Promises. An async function always returns a Promise. await pauses only that function's execution.

async function fetchUser(id) {
  try {
    const res = await fetch(`/api/users/${id}`);
    if (!res.ok) throw new Error('Not found');
    return await res.json();
  } catch (err) {
    console.error(err);
  }
}