(also bar code), n.
a pattern of vertical lines used to encode data on a nonelectronic medium that can be read by an optical scanner and converted to machine-readable language
The Universal Product Code (UPC) is a common form of bar code printed on many items sold in stores, allowing those items to be scanned by automated registers at checkout. Books frequently have a similar bar code that enable machines to read the ISBN. Many bar codes are a single row of lines. Some bar codes are formed from several adjacent rows of lines, each row encoding different data.