title: Reload vs Refresh
body: <p>I have this script</p>
  
  <pre><code>&lt;?php
  header("Expires: Sat, 11 Jun 2011 00:00:00 GMT");
  echo "Hello World";
  ?&gt;
  </code></pre>
  
  <p>It just writes "Hello World" and set the cache to expire on next Saturday. </p>
  
  <p>Now, when I load this page in FireFox and click on reload button, it makes a new request to server to load the page instead of just serving it from cache (I think to ensure if <code>last-modified</code> is still valid).</p>
  
  <p>However, if I put my cursor on the address bar and press <kbd>Enter</kbd>, FireFox serves the contents from cache. </p>
  
  <p>Why is that so? Why does in first case (reload) it makes a request to server, but in second case (refresh, I guess?) it serves from cache?</p>