e., the server receives a request, and the server
satisfies the request with a file transfer, regardless of what has happened before with this client. This
statelessness has been a challenge to those developing applications to be delivered over the web. For
instance, a banking application will need to keep track of the account number of the individual making
inquiries, even though the individual makes repeated inquiries and updates using several different screens
(web pages). How is application state maintained in such applications?
Web applications often use ???cookies??? to store information about the current interaction with the user.
Cookies are files kept on the client??™s computer and facilitated by the client??™s web browser.
A second way of saving information about the current interaction is to use ???hidden fields??? in the web
page sent to the client. The browser does not display these fields to the client, but information saved
from the previous transactions with the client can be stored in the hidden fields, so that the server
has that context available when the user submits his next page to the server.
A third way to save transaction state is with a user session object on the server. When a user logs
in to the server, the server creates a ???session??? on the server that is identified by a session_ID.
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