title: CSS: Is clear both need in different level of div
body: <p>I have this <code>CSS</code> code:</p>
  
  <pre><code>#header {
      width: 100%;
      background: yellow;
  }
  
  #content {
      width: 100%;
  }
  
  #col1 {
      width: 200px;
      float: left;
      background: red;
  }
  
  #col2 {
      width: 600px;
      background: yellow;
      margin: 0px 0px 0px 200px;
  }
  
  #col3 {
      width: 200px;
      float: right;
      background: blue;
  }
  
  #footer {
      width: 100%;
      height: 90px;
      background: black;
      clear: both; **&lt;~ This**
  }
  </code></pre>
  
  <p><code>HTML</code> code:</p>
  
  <pre><code>&lt;div id="header"&gt;&lt;/div&gt;
  &lt;div id="content"&gt;
      &lt;div id="col1"&gt;&lt;/div&gt;
      &lt;div id="col2"&gt;&lt;/div&gt;
      &lt;div id="col3"&gt;&lt;/div&gt;
  &lt;/div&gt;
  &lt;div id="footer"&gt;&lt;/div&gt;
  </code></pre>
  
  <p>Question:
  Is the propertie <code>clear: both</code> need in <code>footer</code> in case of <code>footer</code> different level with <code>colx</code> (col1, col2, col3)?</p>