title: Fetch API vs XMLHttpRequest
body: <p>I know that Fetch API uses <code>Promise</code>s and both of them allow you to do AJAX requests to a server.</p>
  
  <p>I have read that Fetch API has some extra features, which aren't available in <code>XMLHttpRequest</code> (and in the Fetch API polyfill, since it's based on <code>XHR</code>).</p>
  
  <p>What extra capabilities does the Fetch API have?</p>