WordNet (r) 3.0 (2006):

bar code
    n 1: code consisting of a series of vertical bars of variable
         width that are scanned by a laser; printed on consumer
         product packages to identify the item for a computer that
         provides the price and registers inventory information
         [syn: bar code, Universal Product Code]

The Free On-line Dictionary of Computing (30 December 2018):

bar code

    A printed horizontal strip of vertical bars of
   varying widths, groups of which represent decimal digits and
   are used for identifying commercial products or parts.  Bar
   codes are read by a bar code reader and the code interpreted
   either through software or a hardware decoder.

   All products sold in open trade are numbered and bar-coded to
   a worldwide standard, which was introduced in the US in 1973
   and to the rest of the world in 1977.  The Uniform Code
   Council in the US, along with the international article
   numbering authority, EAN International, allocate blocks of
   unique 12 or 13-digit numbers to member companies through a
   national numbering authority.  In Britain this is the Article
   Number Association.  Most companies are allocated 100,000
   numbers that they can use to identify any of their products,
   services or locations.

   Each code typically contains a leading "quiet" zone, start
   character, data character, optional check digit, stop
   character and a trailing quiet zone.  The check digit is used
   to verify that the number has been scanned correctly.  The
   quiet zone could be white, red or yellow if viewed by a red
   scanner.  Bar code readers usually use visible red light with
   a wavelength between 632.8 and 680 nanometres.

   [Details of code?]

   (1997-07-18)