HTTP Multi session


How is managed multiple HTTP request from many different users at a time?
Imagine 2 users accessing a same web page then make different selections then submit the forms, how could we know which selections were made by which user?
Each web page request calls the same cgi, so the datas from the user #1 are mixed with the ones from the user #2.
How to separate the datas from different users?
RpSetUrlState function usage is not clearly explained…