The portion of a computer monitor or a cathode-ray tube on which the image is displayed.
In process photography, a screen is a sheet of film with a particular set of dot patterns that is used to convert a continuous-tone image into a halftone, or a series of discrete dots of varying density. The term screen can also be used as a verb which means to produce a halftone from a continuous-tone image. (See Halftone.)
In digital halftone production, screen refers to the screen algorithms which convert the stored gray levels of the original image to the proper pattern of dots upon output.