What are bar codes?

Bar codes are numerical product codes that appear on the labels of merchandise. A full-length bar code has 12 digits. Each digit is coded by two black and two white stripes that range in width. Each digit represents something different; for example, the first digit indicates the type of product it is; other digits form the manufacturer’s identification number and price. Bar codes were originally created to help grocery stores speed up the checkout process and keep better track of inventory, but the system quickly spread to all other retail products because it was so successful. Barcodes are read by laser scanners called bar code readers or scanned from an image by special software.