Samsung SyncMaster 225MS - Manual (Page 37)

Menu Description
SOURCE
Selects the input signal while the OSD is off.
(When the source button is pressed to change the input mode, a message
appears in the upper left of the screen displaying the current mode -- PC, DVI,
HDMI, AV, S-Video and Component input signal.)
Changing the source is only allowed for external devices that are connected to the
monitor at the time.
PIP (Available in PC/DVI Mode Only)
Menu Description
PIP
Push the PIP button to turn PIP screen On/Off.
You can view a picture from HDMI (PC mode only), AV, S-Video, or
Component (DVI mode only) through the PIP screen in PC and DVI mode.