Learn in the textbookPhysical Security Measures
DefinitionClear screen is the practice of locking the screen whenever you step away so that others cannot see what is displayed.
ExplanationAn unlocked device can not only be viewed but also operated by someone else with the owner's permissions. Setting the screen to lock automatically after a period of inactivity covers the times you forget.
AnalogyIt is like a cashier closing and locking the till before leaving the register. Left open, anyone passing by could look inside and help themselves.
Memory hookDesk is about paper, screen is about the display. Both say "clear", but they tidy different places.