In the past, 9 to 12 inch (diagonal) B/W CCTV cameras monitors were very popular in the field. Nowadays, more and more people are looking for high inches and color monitors. As it known to us, 3 different color dots can produce one pixel of information, so, color monitor usually has lower resolution than B/W monitor.
Single Monitor, Quad Monitor and 4-Channel Monitor
Single Monitor is usually professional monitor with one video input of BNC jack.In order to combine multiple cameras, we should use Quad splitter, video switcher or multiplexer. Quad monitor has built-in quad splitter and usually has 4 DIN jacks for video inputs. 4-Channel Monitor contains 4 channel video switcher inside and usually has 4 DIN jacks for video inputs. Quad Monitor or 4-Channel Monitor is usually a part of packaged observation system and does not match other manufacturer's camera or cable.