UPC — The Basics
UPC, which stands for Universal Product Code, is a system for identifying consumer products from a unique, 12-digit number and an associated barcode. Most retail items in the United States and Canada include a UPC on their packaging.
The UPC system was created to make it easy for retailers to match up a physical product, fresh off the shelf, with the electronic record in their Point of Sale (aka, POS) system. By scanning the barcode present on each item sold, the retailer checkout process becomes much more efficient, and it can help with stocktaking as well.
A new UPC number is generally assigned to every unique product that a manufacturer produces. This can include product "variants" too. So, for example, a particular type of shoe may have ten or more UPCs assigned to it, one for each size the shoe comes in.
History of the UPC Barcode Standard
Basic barcode technology has roots going back to at least the early 1900s, but the UPC system was first developed in the 1970s by the Uniform Product Code Council (today known as GS1). Several large technology firms were involved in the system's development, not least being IBM, whose proposal was eventually chosen as the one for implementation.
Although initially intended for use in grocery stores to speed up the checkout process, by the 1980s its adoption had broadened to retailers of all kinds. And as anyone that has shopped in the last 20 years can likely attest to, the UPC is now ubiquitous and few retail products come without it (in North America at least).
Tradition states that the first UPC to be scanned was for a pack of gum — Wrigley's Juicy Fruit — in 1974, at a supermarket in Troy, Ohio.