To designate certain cells as header cells, use the <th> tag instead of the <td> tag, where “th” stands for table header.
Example
Designate the initial row as containing table header cells.
| <table> <tr> <th>Person 1</th> <th>Person 2</th> <th>Person 3</th> </tr> <tr> <td>Emil</td> <td>Tobias</td> <td>Linus</td> </tr> <tr> <td>16</td> <td>14</td> <td>10</td> </tr> </table> |