Referring to a period of time during which there is a logical association, i.e., communication, between two or more stations, terminals, or systems. A session may be established through a log-on procedure and terminated by a log-off procedure. A network administrator might limit the duration of a session, at the expiration of which time the session will be timed-out, or involuntarily terminated, in order to ensure that network and system resources are shared fairly among the universe of active users. A session also may time out if no activity is detected for a predetermined period of time.