title: background:none vs background:transparent what is the difference?
body: <p>Is there a <strong>difference between</strong> these two CSS properties:</p>
  
  <pre><code>background: none;
  background: transparent;
  </code></pre>
  
  <ol>
  <li>Are they both valid?</li>
  <li>Which one should be used and why?</li>
  </ol>