3 tier will optimize the resource utilization and improve your program drastically. You wont feel it when you are building simple application when large applications you will clearly get difference. For example take a look at how this 3 tier is used and see the difference.
public class businesscheck
{
datacheck dldata = new datacheck();
public int PeronalDetails(int bh, string bse, string bt, string bde)
{
string sql = "[dbo].[newsinsert]";
int bheader = bheaderid + 1;
int result = dldata.SQLSP(sql, bheader, bsubtype, btitle, bdescr);
return result;
}
public void deleterecord(int a)
{
dldata.SQLC();
}
}
Then finally when you call this from your front layer system can easily pass the values and programmers and designers can work separately.
protected void Button1_Click(object sender, EventArgs e)
{
int MyInteger = Convert.ToInt32(TextBox1.Text);
string subtype = txt2.Text;
obj1.PeronalDetails( header, subtype, title, desc);
txt2.Text = "";
}