What is a...............
What they are.........
LCD and CRT
Most desktop displays use liquid crystal display(LCD) or cathode ray tube (CRT) technology. While nearly all portable computing devices such as laptop incorporate LCD technology. Because of their slimmer design and lower energy consumption, monitors using LCD technology (also called flat panel or flat screen displays) are replacing the CRT on most desktops.
How does a LCD work?
Liquid crystal display technology works by blocking light. Specifically, an LCD is made of two pieces of polarized glass that contain a liquid crystal material between them. A back light creates light that passes through the first glass. At the same time, electrical currents cause the liquid crystal molecules to align to allow varying levels of light to pass through to the second glass and create the colors and images that you see.