LCD is short for liquid crystal display, a type of display used in
digital watches and many portable computers. LCD displays utilize
two sheets of polarizing material with a liquid crystal solution
between them. An electric current passed through the liquid causes
the crystals to align so that light cannot pass through them. Each
crystal, therefore, is like a shutter, either allowing light to
pass through or blocking the light.
Monochrome LCD images usually appear as blue or dark gray images
on top of a grayish-white background. Color LCD displays use two
basic techniques for producing color: Passive matrix is the less
expensive of the two technologies. The other technology, called
thin film transistor (TFT) or active-matrix, produces color images
that are as sharp as traditional CRT displays, but the technology
is expensive. Recent passive-matrix displays using new CSTN and
DSTN technologies produce sharp colors rivaling active-matrix
displays.
Most LCD screens used in notebook computers are backlit, or
transmissive, to make them easier to read.