title: browser image downloading behaviour
body: <p>In a question I've seen here, someone asked how to alter the background when the page was refreshed, without using any server side techniques. One answer was to make this the css</p>
  
  <pre><code>.backgr0 { background-image: url('images/somepic.jpg'); }
  .backgr1 { background-image: url('images/somepic.jpg'); }
  .backgr2 { background-image: url('images/somepic.jpg'); }
  .backgr3 { background-image: url('images/somepic.jpg'); }
  .backgr4 { background-image: url('images/somepic.jpg'); }
  </code></pre>
  
  <p>and then have a random class added to the element.</p>
  
  <p>But what I was wondering is, when the browser encounters this css, does it go ahead and download all these images? Because in that case, you're really raising the ammount of HTTP requests.</p>