title: Why does the CheckBox Html Helper render a hidden input field?
body: <p>I often use the built in CheckBox HtmlHelper as it allows me to easily specify the checked state of the element like this  </p>
  
  <pre><code>@Html.CheckBox("Test",Model.IsChecked);
  </code></pre>
  
  <p>vs creating it on the view like so </p>
  
  <pre><code>@if(Model.IsChecked)
  {
    &lt;input id="test" type="checkbox" checked="checked" /&gt;
  }
  else
  {
    &lt;input id="test" type="checkbox"  /&gt;
  }
  </code></pre>
  
  <p>However when inspecting the html generated by the helper i can see it renders this html.</p>
  
  <pre><code>&lt;input id="Test" name="Test" type="checkbox" value="true" /&gt;
  &lt;input name="Test" type="hidden" value="false" /&gt;
  </code></pre>
  
  <p>I can't work out why there is a hidden field input as well, what is it used for? </p>