Nidhi... you confused about storing session info and the mvc model and how
applets in pages and multple pages...
It works like this... when the first request comes in and you have sessions set... if gives the browser a number...
JSessionID = 173746465238238292932398932
A long unique number...
Then after that the browser regardless of the page or applet comms or whatever always send that number back to the server.
So the data is not actually comming from the browser, just the number is.
From that number its able to look up what you stored previously because the data never left the server.
So... if you get send from a servlet and then get it back in a JSP page or the applet, or next page.... the servler can find it from the sessionID.
Thats more or less it... same trick is uses when you logon in one page and then move to other pages... thats how servlet container remembers you log on.