Universal Product Code

The Universal Product Code (UPC) is a barcode symbology that is widely used in the United States, Canada, United Kingdom, Australia, New Zealand, and in other countries for tracking trade items in stores.

UPC (technically refers to UPC-A) consists of 12 numerical digits, that are uniquely assigned to each trade item. Along with the related EAN barcode, the UPC is the barcode mainly used for scanning of trade items at the point of sale, per GS1 specifications. UPC data structures are a component of GTINs and follow the global GS1 specification, which is based on international standards. But some retailers (clothing, furniture) do not use the GS1 system (rather other barcode symbologies or article number systems). On the other hand, some retailers use the EAN/UPC barcode symbology, but without using a GTIN (for products, brands, sold at such retailers only).

Wallace Flint proposed an automated checkout system in 1932 using punched cards. Bernard Silver and Norman Joseph Woodland, a graduate student from Drexel Institute of Technology (now Drexel University), developed a bull's-eye style code and applied for the patent in 1949 (US patent 2612994, Norman J. Woodland and Bernard Silver, "Classifying Apparatus and Method", issued October 7, 1952 ).

In the 1960s, railroads experimented with a multicolor barcode for tracking rail cars, but they eventually abandoned it.

...
Wikipedia