(
Liquid 
Crystal 
Display)  A screen display technology developed in 1963 at the David Sarnoff Research Center in Princeton, NJ.  All computer and most TV screens are LCDs (see 
LED TV), while mobile device screens may be LCD or organic LED (see 
OLED).  By the 1990s, color LCDs helped laptop sales boom, and LCD computer monitors outsold CRTs for the first time in 2003.  See 
liquid crystal, 
LCD types and 
LCD categories.
A Color Pixel
Sandwiched between polarizing filters and glass panels, rod-shaped molecules of liquid crystals flow like liquid and bend light like crystal.  The liquid crystal layer is 5 to 25 micrometers thick (2 to 10/10,000" inch).  For more details on color LCDs, see 
LCD subpixels.
Because it took so little power to move crystal molecules, LCD wristwatches and other monochrome screens began to flourish in the late 1970s.  For more details on this type of display, see 
seven-segment display.  
(Image courtesy of the private collection of Peter Wenzig.)LCDs and LEDs are widely used in combination as in this printer panel.  Readouts are LCDs, but the indicator lights on billions of products are LEDs.  LCD TVs use LED backlights (see 
LED and 
LED TV).  See 
LCD vs. OLED and 
LCD vs. plasma.