constituent, element, component - an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system; "spare components for cars"; "a component or constituent element of a system"

raster - formation consisting of the set of horizontal lines composed of pixels that is used to form an image on a CRT

computer science, computing - the branch of engineering science that studies (with the aid of computers) computable processes and structures