title: CSS: height:100% vs bottom:0
body: <p>What is the essential difference between:</p>
  
  <pre><code>position: absolute;
  top: 0;
  height: 100%;
  </code></pre>
  
  <p>and</p>
  
  <pre><code>position: absolute;
  top: 0;
  bottom: 0;
  </code></pre>