A sync generator produces a central timing reference (usually a color black signal, also known as a black and burst) that is distributed throughout a facility.
The central timing reference is used in video production to synchronize the timing of a video source signals.
As a result, the timing or alignment of the video frame can be adjusted so that the start of the upper left corner scan line of the image occurs simultaneously on all video equipment in the network.
This is an absolute requirement for both analog and digital systems in order to perform video effects or glitch-free source switching.
This article about television technology is a stub.