A quad, as it's name implies, takes 4 video inputs and manipulates them so that they can be viewed on one screen. Some things to take into account when choosing a quad are: B/W or color, real time or time lapse, front panel controls or not. Quads in and of themselves do not record any video, the output of the quad must be connected to a recording device ( DVR or VCR) in order for recording to take place. If your having trouble selecting the right quad for you, then please visit the CCTVhelp.com forum for support