Server Transfer :
1. To transfer page processing from one page directly to 
the next page without making a round-trip back 
     to the client's browser we use Server Transfer .
2. Server Transfer provides a faster response with a little 
less overhead on the server.  
3. The clients url history list or current url is not 
updated by the Server Transfer.  


Response Redirect :
1. To redirect the user's browser to another page or site 
Response.Redirect is used.
2. This performs a trip back to the client where the 
client's browser is redirected to the new page.  
3. The user's browser history list is updated to reflect 
the new address.

Server Transfer can only redirect to the pages (URL)which 
are available within that server and can carry the control 
state while transferring.

Response Redirect allows you to transfer to the pages (URL)
which might or might not available in that web server. and 
cannot carry the control state while transferring.