The HTML <colgroup> tag is used to apply different styles or properties to group of column. It reduce the repetition the style for each cell, for each row.
Example of Code
<table>
<colgroup>
<col span="4" style="background-color:red">
<col style="background-color:yellow">
</colgroup>
<tr>
<th>ISBN</th>
<th>Title</th>
<th>Price</th>
</tr>
<tr>
<td>3476896</td>
<td>My first HTML</td>
<td>$53</td>
</tr>
<tr>
<td>5869207</td>
<td>My first CSS</td>
<td>$49</td>
</tr>
</table>
Output
ISBN Title Price 3476896 My first HTML $53 5869207 My first CSS $49
