The first computer monitor was a panel of light bulbs
Engineers on early computers watched rows of bulbs, each showing whether one bit inside the machine was on or off. That panel let them monitor the computer, and the name stuck to every screen since. For decades it was a supporting act: real output went to line printers, while the lights just showed that a program was running.
Cathode ray tubes took over next. Before home computers arrived in the late 1970s, a tube was often built into one bulky terminal with its keyboard, imitating a paper teleprinter so closely that people called it a glass teletype. Text was monochrome, large and blurry. High-resolution tubes existed for military and scientific work but cost far too much until the slow yet affordable Tektronix 4010 of 1972. Colour spread through home machines such as the 1977 Apple II and Atari's 8-bit computers of 1979, often plugged into an ordinary television. IBM's 1981 colour adapter showed four colours at 320 by 200 pixels; its 1984 successor managed 16.
By the late 1980s good computer monitors could show high-definition video while broadcast television, after repeated failed attempts at HD standards, stayed stuck at standard definition into the 2000s. Liquid-crystal panels first earned their keep in 1990s laptops, where low power and light weight justified the price. Standalone LCDs appeared in the mid-1990s at steep prices, and in 2003 they finally outsold tubes. Around 2010 both TVs and monitors shifted from the squarish 4:3 shape to widescreen 16:9, following films and games.
The swap was not all gain. LCDs are lighter, thinner, flicker-free and sharper at their native resolution, but early ones smeared moving images, and tubes still beat them on black levels, viewing angle and response time. Vision scientists, who need precise timing, have kept using CRTs. OLED screens combine many strengths of both, though like tubes and plasma they can suffer burn-in and cost more.
Buyers now weigh a list of numbers: resolution and pixel density, brightness in nits, contrast ratio, refresh rate and response time. Colour depth matters too. Panels with 10 bits per channel can show around a billion shades, against roughly 16.8 million for standard 8-bit screens.
Source: Computer monitor
