The term monochrome means one color or multiple shades of one color. For example, grayscale is considered monochrome, which is a range of gray shades from white to black.
Monochrome in computing
When speaking of computers, monochrome was used to describe early CRT computer monitors that only displayed one color. The most common color used was green, but amber or white were also used. Whichever color a monitor used would be the color of the characters or graphics that would show up on the dark background. In the 1980s, multi-color screens were introduced. Although color screens quickly became the standard, monochrome still continued to be used but became obsolete by the time that the LCD screen was introduced.
Monochrome vs. grayscale vs. black and white
When used in terms of design, monochrome often refers to something that is made up of multiple shades of one color. This idea can also be applied to photography. There are some terms used interchangeably but can have different meanings.
Black and white and grayscale essentially mean the same thing. The term black and white was coined after the invention of color photography because there needed to be a way to distinguish the two. Grayscale is more accurate because black and white images are not only made up of black and white, but also in-between shades of gray.
While anything that is grayscale is monochromatic because it is made up of varying shades of gray, not everything that is monochromatic will be grayscale. For example, photos or videos that are shot in night vision mode appear in green monochrome.
