There are basically three method in asp.net to redirect one page to another :
 Response.Redirect("default.aspx");
 simply redirect from one page to another page and url also change ..................
 Server.Transfer("default.aspx");
redirct one page to another page but url cannot change...................................
 Server.Execute("default.aspx");
brought content of targat page on the same page and render both page simultaneously.............