rownspan attribute

A table is a rectangular grid with rows and columns. The content of a cell can be extended over the content of the adjacent cells using the rowspan attributes of the <td> or <th> elements.

The possible values for the rowspan attributes are positive integers representing the number of columns or rows occupied by the extended cell.

To extend the cell, only the <td> or <th> element id required to define the content of the cell.
Related Tutorial
1. tables
14. alignment