Specifies groups of columns in a table. It is used to assign attribute values to a group columns for formatting. This tag can only be used within the table tag.
<colgroup attributes></colgroup>
<table>
<colgroup span=”3” style=”color:red;”></colgroup>
<tr>
<td>row one</td>
</tr>
<tr>
<td>row two</td>
</tr>
</table>