How the barcode works?
For readers not familiar with how the technology works, the following is a brief tutorial.
Linear bar codes encode information in one dimension, horizontally, through various combinations of dark bars and light spaces and typically encode around 20 characters of data. The Universal Product Code (U.P.C.) symbols scanned at the checkout are the most familiar of the linear symbologies. Unknown to the general public, UPC symbols contain only 12 numeric digits to identify the product. Many would be surprised to know that the price is not actually encoded in the symbol, but contained in a data base that might not even be located in the same building.