The thing Your probably looking at!
Cathode ray tube
Cathode ray tube (CRT) was the first form of visual display on a computer the screen was attached to the rest of the computer from the back so the computer could not fold-up to become smaller. The image flickered, was monochrome and was in poor resolution. Some people today use it because it is cheaper despite the fact the technology is thirty years old
Liquid crystal display
More modern computers use Liquid crystal display (LCD) because they can be used in laptops, they use less more and they are lighter, these factors justify the higher price. The first LCD on the market appeared in the mid 1990s and sold for very high prices. Apple soon saw the opportunities in this new technology and developed the Apple Studio Display and the Apple Cinema Display in 1998 and 1999.