HOW BAR CODES DEVELOPED
Bar code technology became available in 1974. Since then, several bar code systems have been designed. Each system is based on creating a unique identification number for every manufacturer. One system uses 12 -digit identification numbers. Each printed bar code consists of a unique pattern of black and white lines that represent numbers from 0 to 9. The first six digits identify the manufacturer. The next five digits identify a certain product. The last digit is called a check digit. It tells if the number scanned correctly. For example, the Camp bell Soup Company produces canned foods.