A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, the Ubuntu operating systems need to provide users with the ability to manually invoke a session lock so users may secure their session if they need to temporarily vacate the immediate physical vicinity. Fixtext: Install the "vlock" package (if it is not already installed) by using the following command: $ sudo apt-get install vlock

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Install the "vlock" package (if it is not already installed) by using the following command: $ sudo apt-get install vlock