From The Art and Popular Culture Encyclopedia
An icon (from Greek eikon, "image") is an image, picture, or representation; it is a sign or likeness that stands for an object by signifying or representing it, or by analogy, as in semiotics; in computers an icon is a symbol on the monitor used to signify a command, file or record; by extension, icon is also used, particularly in modern popular culture, in the general sense of symbol — i.e. a name, face, picture, edifice or even a person readily recognized as having some well-known significance or embodying certain qualities. one thing, and image or depiction, that represents something else of greater significance thru literal or figurative meaning, usually associated with religious, cultural, political, and economic standing.
Throughout history religious cults or religious cultures have been inspired or supplemented by concrete images, whether in two dimensions or three. The degree to which images are used or permitted, and their functions, whether they are for instruction or inspiration, whether treated as sacred objects of veneration or worship or simply applied as ornament, depends upon the tenets of a given religion in a given place and time.
In Eastern Christianity and other icon-painting Christian traditions, the icon is generally a flat panel painting depicting a holy being or object such as Jesus, Mary, saints, angels, or the cross. Icons may also be cast in metal, carved in stone, embroidered on cloth, done in mosaic work, printed on paper or metal, etc. Creating free-standing, three-dimensional sculptures of holy figures was resisted by Christians for many centuries, while the fear that daimones inhabited pagan sculptures remained strong.