QSG : Acronym for Quick Start Guide. A QSG is a short manual or pamphlet shipped with a product to assist the installer/operator in completing the initial installation.
Quad : The name given to a video device that displays four cameras on a single monitor. The quad hardware digitizes each of the four camera images and resizes them to fit in the quad format.
Quad screen : Display where 4 cameras are viewed on the same screen, each camera image occupying a quarter of the display area. Quad screens can be seen in devices with any number of camera inputs. The quad screen is just one of several multi-screen formats available.