optical bar code
- A precise arrangement of parallel vertical bars and spaces of varying widths, encoded with characters such as letters, numbers, or symbols. These bars are read by optical devices called bar code readers, which may scan the data horizontally and/or vertically, or at any angle. These serve for rapid and error-free entry of information, and are used, for instance in retail stores, libraries, or to help robots identify components in assembly facilities. Also called bar code.