from
The Free On-line Dictionary of Computing (8 July 2008)
Advanced Power Management
APM
green monitor
<hardware> (APM) A feature of some displays, usually but not
always, on {laptop computers}, which turns off power to the
display after a preset period of inactivity to conserve
electrical power. Monitors with this capability are usually
refered to as "green monitors", meaning environmentally
friendly.
Not to be confused with a {screen blanker} which is {software}
that causes the display to go black (by setting every {pixel}
to black) to prevent {burn-in}.
(1997-08-25)