Universal Product Code - WikipediaA UPC barcode The Universal Product Code (UPC or UPC code) is a barcode symbology that is used worldwide for tracking trade items in stores. The chosen symbology has bars (or spaces) of exactly 1, 2, 3, or 4 units wide each; each decimal digit to be encoded consists of two bars and two spaces chosen to have a total width of 7 units, in both an "even" and an "odd" parity form, which enables being s
