Is the predominant technology used in flat panel displays. The principle that makes the display work is this: A crystalìs alignment can be altered with an electric current. If the crystal is lined up one way ñ it will allow the light waves to pass through a polarised filter, but if the electric current alters the crystalìs alignment, it will guide light so that the polarised philtre blocks the light. By densely packing red, blue and green light emitting crystals next to each other on a sheet (ìcalled a substrateî), one can create a full colour display. The great thing about LCD is that the crystals can be packed together closely, allowing for a higher-resolution, finer-detail display. The con is that LCDs are somewhat fragile, require a lot of power and are relatively less bright.