The data transfering between two page will be more differ on server.Transfer() and Response.Redirect().

Server.Transfer

Server.Transfer() helps the one less round trip. The main advantage of this transfer the first page to second page with better performance. The data can pass through variables, query string and also can retrive from the previous page control value.

Eg: Server.Transfer("Default.aspx");

Response.Redirect()

It is very similar to server.Transfer. The main difference is the posted pervious page values can't be accessable. Here also the data can pass through server variables and query string. It simply redirect the page from one page to another.

Eg: Response.Redirect("Default.aspx")

Note: But the pervious page values can't be accessable by Response.Redirect().