Table heading tags <th> ... </th> are used to designate a cell as a header. These tags should be used with in <tr> ... </tr>. By default, the content of the header row is center aligned and appears in bold face.

          Example:

          <table border=1>
              <tr>
                <th>Cell 1 </th>
                <th>Cell 2 </th>
                </tr>
                <tr>
                <td>Cell 3 </td>
                <td>Cell 4 </td>
                </tr>
          </table>

          Above code defines a table with two rows and four cells as below.