the control panel
duplicate:.With a single computer you can look at things on two screens
extenden displays: Expanded screens: you can put something different on each monitor and you can move them on screen
only monitor 1: miras la misma imagen en dos pantallas ala vez
only monitor 2: You look at the image on one monitor alone and turn off the other to save energy for example when you watch a movie with the projector you can turn off the computer screen so it does not dazzle you
