Sync converters change the sync type associated with your video signal. All video communications include two sync signals, which allow a monitor to lock on to the signal and display a stable image. One sync signal is for the horizontal, one for the vertical. There are three types of sync generation; separate sync, composite sync, and sync on green. Separate sync is when the sync signals are sent on two separate wires on the cable. Composite sync is when the sync signals are sent on their own, dedicated wire in the cable. Sync on green is when the sync signals are sent on the same wire, which is the same wire that the green color signal uses. The VGA standard uses a separate sync signal. Sun workstations used composite sync. HP, DEC, and SGI workstations used a sync on green signal.