WHAT IS ROUND TRIP AND WHAT IS POSTBACK?

WHEN A USER INTERACTS WITH WEBFORM ,BROWSER HAS TO RESPOND TO WEBSERVER WITH SOME CLIENT SIDE SCRIPTING AND NEEDS TO SEND SOME INFORMATION TO THE WEB SERVER TO PROCESS. 

       WHEN SERVER SIDE PROCESSING IS INVOLVED ,THE TYPICAL INTERACTIVE USER SESSION TAKES PLACE IN FOLLOWING STEPS:

1.THE USER SENDS REQUEST TO WEB SERVER FOR WEBFORM.

2.THE WEBSERVER RESPONSE FOR OUR REQUEST.

3.THE USER ENTERS THE DATA AND SUBMITS TO THE SERVER.

4.THE WEBSERVER PROCESS IT AND  GIVES THE RESULT BACK TO THE USER

         3-IS NOTHING BUT POST BACK

         4-ROUND TRIP