<colgroup> - HTML 5

The <colgroup> tag specifies a group of one or more columns in a table for formatting.
The <colgroup> tag is useful for applying styles to entire columns, instead of repeating the styles for each cell, for each row.
Note: The <colgroup> tag must be a child of a <table> element, after any <caption> elements and before any <thead>, <tbody>, <tfoot>, and <tr> elements.
Tip: To define different properties to a column within a <colgroup>, use the <col> tag within the <colgroup> tag.
Attribute : 
span (number) - Specifies the number of columns a column group should span

Syntax

<colgroup>

</colgroup>

Example

 <table>
  <colgroup>
    <col span="2" 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>
</table> 

Output / Return Value

Limitations

Alternatives / See Also

Reference