[eluser]WanWizard[/eluser]
Can you explain what you exactly mean by that?
Sessions are about two things. Maintaining session state (a link between the browser and the application) and storing session information.
To maintain state, every session solution uses a cookie. That cookie should be encrypted, and should only contain enough information to maintain the state (usually only the session ID, sometimes some extra security checks like IP or browser info). You store session information server side, to make sure it's save. The CI session library uses a database table for that, there are third party options available that use other types of storage.
You can use other cookies as well, just use the set_cookie() and get_cookie() methods. But these don't have anything to do with the session.