When you open a webpage, it is as if you have never been there before, unless you code explicitly checks and loads information into it.
Normally, this information would be stored in the Session or in Cookies.
Session[
^] for data you want to throw away when the browser is closed (or before).
Cookies[
^] for data that you want to preserve even if the PC is powered down and restarted. (Shopping baskets are an example)