Which means sellers on the Amazon market will need to have a product code on all gadgets they are promoting on-line. A bar code is made up of bars detailed reviews and ratings spaces of varying width discovered on packages of merchandise bought in every single place. The parallel lines of a bar code symbolize a language of letters and numbers. UPC barcodes were initially created in the early 1970s to determine merchandise and help grocery shops pace up the checkout process and keep higher monitor of stock, but the UPC code system caught on quickly in different retail areas as a result of it was so successful.