Mosaic in the broadest sense of the term means a work that is a drawing or painting on a surface created by bringing together solid objects.
Karl Otfried Müller, Handbuch der Archäologie der Kunst, 1830
Images can be made up of individual picture elements. The design of an image, ornament or type face is broken down into pixels (picture elements). In carpets and mosaics, these pixels have their own specific colours. Halftone printing breaks images down in order to print half tones in the form of individual dots; in modern printing, this has become color halftoning using the four primary printing colours cyan, magenta, yellow and black in accordance with the principle of the subtractive colour model. Computer screens (monitors) make use of the principle of raster graphics on the basis of additive colour mixtures of red, green and blue.
Mosaic as an artistic technique goes back to the Sumerian period in Mesopotamia. In Ancient Greece and Rome, mosaics made of polished stones, ceramic and glass were widely popular. The technique of creating images out of individual dots of colour is used universally in both art and technology.