Im going to expail the various difference between GridView and the DataGrid controls and their different logics.

The GridView and the DataGrid controls have a different logics.

GridView can bulid pages on mobile devices

DataGrid in  1.x doesn't supports the themes however in 2.0 it perform themes.

The DataGrid in version 2.0 can also render adaptively,

GridView supports the classic bindingbased on the DataSource property.

GridView provides the option for paging ,sorting in easy click of a button however datagrid required some coding

· Richer design-time capabilities.
· Improved data source binding capabilities.
· Automatic handling of sorting, paging, updates, and deletes.
· Additional column types and design-time column operations.
· A Customized pager user interface (UI) with the PagerTemplate property.

· Different custom-paging support.
· Different event models.

HTML

 <asp:DataGrid ID="DataGrid1" runat="server" OnPageIndexChanged="DataGrid1_PageIndexChanged"
 AllowPaging="true" PageSize="5" OnSelectedIndexChanged="d1_SelectedIndexChanged">
 </asp:DataGrid>  


Codebehind

protected void DataGrid1_PageIndexChanged(object source, DataGridPageChangedEventArgs e)
    {
      DataGrid1.CurrentPageIndex =  e.NewPageIndex 
      BindGrid();// Grid binding method
    }

 <asp:GridView ID="GridView1" runat="server" OnPageIndexChanging="DataGrid1_PageIndexChanging"
  AllowPaging="true" PageSize="5" OnSelectedIndexChanged="d1_SelectedIndexChanged">
  </asp:GridView>  

Codebehind

protected void GridView1_PageIndexChanged(object source, DataGridPageChangedEventArgs e)
    {
      GridView1.PageIndex =  e.NewPageIndex 
      BindGrid();// Grid binding method
    }   

It allows for the mix both data bound and unbound, virtual columns in the GridView.

It has a special virtual mode allowing for the display of more than 100.000 rows without a huge performance hit.

Individual columns, rows, cells or an entire data source can easily be styled.

private void InsertDataGridColumn()
{
DataSet dataset = new DataSet();
DataGridTableStyle TStyle = new DataGridTableStyle();
DataTable table = dataset.Tables["Student"];
TStyle .GridColumnStyles[0].MappingName ="Stid"
TStyle .GridColumnStyles[0].HeaderText = "Student ID";
TStyle .GridColumnStyles[0].Width = 150;
DataGrid1.TableStyles.Add(TStyle );
}

The above example is used for DataGrid TableStyle.

DataGridView control designing operations are done through the IDE design layout window via drag and drop.

We can extend the DataGridView control in a number of ways to build custom behaviors into your applications .

The above article describes the simple diff logics between GridView and DataGrid Controls.