Bar Code
A barcode is an optical, machine-readable, representation of data relating to the object to which it is attached. Originally barcodes systematically represented data by varying the widths and spacings of parallel lines, and may be referred to as linear or one-dimensional (1D). Later they evolved into rectangles, dots, hexagons and other geometric patterns in two dimensions (2D). Although 2D systems use a variety of symbols, they are generally referred to as barcodes as well.
The first commercial use of barcodes was on metal cans in 1966. The UPC (Universal Product Code) system was invented in 1973 for marking products during manufacture so that they could be scanned at retail checkouts. The first articles about barcodes appeared in the 1970s. In 1974 Kroger grocery stores in Cincinnati used 2D barcodes to automatically scan pricing information at checkout counters.
