What is the method to customize columns in DataGrid ?

We can use the Template Column for customizing columns in DataGrid.
Example: 

<asp:TemplateField HeaderText="Birth Date">
  <ItemTemplate> 
    <asp:Label ID="BirthDateLabel" Runat="Server" 

       Text='<%# Eval("BirthDate", "{0:d}") %>' />
  </ItemTemplate>
  <EditItemTemplate>
    <asp:Calendar ID="EditBirthDateCalendar" Runat="Server" 
      VisibleDate='<%# Eval("BirthDate") %>' 

      SelectedDate='<%# Bind("BirthDate") %>' />
  </EditItemTemplate>
</asp:TemplateField>