innerHtml and server control

Question

Hi, Ihave this code,  I guess this is not a contorl like other server controls like <asp: button ..etc.... now my question, why would I give an id to this tag  <td ? is it because I want to control its content from code behind via        Please confirm and if you have addional answers, please share it with me.  ... thanks
n1.InnerHtml = txtName.Text; 
n1.InnerHtml = txtCountry.Text;
           <tr>
                        <td id="n1" runat="server">
                              Alfa
                        </td>
                        <td id="c1" runat="server">
                              US
                        </td>
                  </tr>