From Consumer Wiki
The universal product code symbol is a graphic representation of the Universal Product Code (UPC) code. It is in the form of a series of parallel light and dark bars of different widths which appears on products for pricing purposes. The numbers printed below the machine readable symbol allow for human reading of the code number. The symbol prevents tampering, and even poor printing should not result in scanning devices reading a wrong number. When the products are passed over a window on the counter, the electronic scanner under window reads the bar code symbol which identifies the manufacturer, the product, and price. The code symbol is also readable by hand-held reading devices.
Once UPC product identification numbers are assigned, their use extends beyond bar coding and scanning. Electric Data Interchanges (EDI) standards have been established in the grocery band retail industries as a common set of formats for computer trading partners. The UPC replaces mail, telephone, and other communication processes.
Uniform Product Code Council, Inc.
7887 Washington Village Drive, Suite 300
Dayton, Ohio 45459