session will keep track of user interaction of a single client

cookies are the ones which are the small server side
entities to store the client side data inside it.

we r all familiar with the method given below

HttpSession session==request.getSession(true);
what happen here

Container whenever gets a request for a session from a client,
it checks out whether the request is for existing or a new
one,how it does.


If a new session: creates a cookie(small text file) ,stuffs
the session id ,and send it to the client as apart of
response headers (Set Cookie:)

existing one---gets the sessionid ,searches for the matching
session and associate with the  request.

Now thing if ur browser is cookies disable, what will happen
next?? :)