title: Grid ColumnDefinition Width : difference between * and <ColumnDefinition/>
body: <p>I've frequently seen these two definitions for columns:</p>
  
  <pre><code>            &lt;Grid&gt;
                  &lt;Grid.ColumnDefinitions&gt;
                      &lt;ColumnDefinition Width="*" /&gt;
                      &lt;ColumnDefinition Width="*" /&gt;
                  &lt;/Grid.ColumnDefinitions&gt;
  </code></pre>
  
  <p>and </p>
  
  <pre><code>                &lt;Grid&gt;
                      &lt;Grid.ColumnDefinitions&gt;
                          &lt;ColumnDefinition /&gt;
                          &lt;ColumnDefinition /&gt;
                      &lt;/Grid.ColumnDefinitions&gt;
  </code></pre>
  
  <p>As I understand it, both divide a grid into two columns with the same width. Are there any differences or conventions?</p>