title: Why use defer with Google Maps Javascript?
body: <p>The Google Maps javascript does some heavy DOM manipulation. Even so, <a href="https://developers.google.com/maps/documentation/javascript/tutorial" rel="noreferrer">the fine docs</a> suggest to load it with the <code>defer</code> flag:</p>
  
  <pre><code>&lt;script src="https://maps.googleapis.com/maps/api/js?key=YOUR_API_KEY&amp;callback=initMap" async defer&gt;&lt;/script&gt;
  </code></pre>
  
  <p>Why would the <code>defer</code> flag be suggested for a script that performs DOM manipulations? <strong>I ask to learn both about the <code>defer</code> flag and to learn about the Google Maps API</strong> as I seem to have a misunderstanding about what one of them is doing.</p>