CRT monitors are bulky and consume a lot of power. LCD monitors have flat screens and low power consumption, but they are much more expensive. They are mostly used with laptops. Each screen pixel has three liquid-crystal cells, one for displaying red, one for blue, and one for green. The liquid crystals are rod-shaped molecules that flow like a liquid. Normally, they are transparent and pass light straight through, but an electrical charge alters their orientation and hence alters the orientation of light passing through them and this gives them a colorful appearance. LCD monitors have different types. The best is the thin-film transistor (TFT) where each of the three pixel cells is charged using a separate transistor. Hence, TFT screens are much brighter and give clearer pictures. They are represented by a matrix of charging transistors and that is why they are frequently referred to as active-matrix LCDs.
