Cathode ray tubes are used in TV monitors and many projection devices, and are familiar to most as the bulky, glass tube contained in most TV sets. Besides bulk, CRTs also consume more energy than LCDs and are also known to emit harmful radiation. Liquid crystal displays use a very thin screen made of two polarizing transparent panels and a liquid crystal surface in between.
Voltage is applied to certain areas, which causes the crystal to turn dark.
A panel light source is transmitted through the transparent crystals and is partially blocked by dark crystals. LCD Contrast is limited because light is only partially blocked in dark areas and aren't able to create deep blacks. LCD monitors usually work well in one resolution. While other resolutions can sometimes be displayed, the image is either not full-screen or image quality may be poor. An NTSC TV image has 525 horizontal lines per frame.