ON and OFF control power to the projector.
PC, VGA, and HDMI are inputs that can display on the projector.
PC: Displays what's on the local podium computer.
VGA: Displays a laptop connected to the VGA cable.
HDMI: Displays a laptop (or another device) connected to the HDMI cable.
DISPLAY MUTE: Also called "picture mute". Stops the projector from displaying the selected device without powering off.