Bar codes are simple machine readable codes that the computer can reproduce directly into the bit streams of zeros and ones which is the machine language of computers. The information or data is encoded using the width of printed bars, width of space between bars, and relative positions of wide or narrow bars and spaces (that is, a unique thick and thin combination of black and white bars).
The equipment used to read the code is called the scanner, which converts the dark bars and white spaces into equivalent Os and Is which computers can understand.
The information in the bar code can contain anything from country of origin, manufacturer’s name and product detail. In fact, the amount of information that can be stored in these labels is limited only by the choice of symbology. Symbology is the term used to describe the rules specifying the way data is encoded into bars and white spaces.
To give an example, the UPC A version bar code, is shown with the codes 05 1111 2 8 8 17. UPC is the Universal Product Code, widely adopted in retail stores to indentify products. The first digit 0 can stand for the country code, the next five digits (5 1 1 1 1) for the manufacturer’s code and the next five digits (2 8 8 1 7) for the product, and the last digit is called the check digit used for checking the accuracy of the reading system.
The computer checks the code and matches it with information in its own database and does the identification. It simplifies billing and inventory of products. The billing person has only to scan the label of different items sold and the bill is printed almost instatantaneously, saving time for the customer and the clerk. The other important benefit is that the inventory is automatically updated, without the need for laboriously checking each and every item, at the end of the day.
If EDI (electronic data interchange) is integrated, the system automatically prepares a buying order for items which are about to be sold out based on a predetermined stock set by the store manager, Bar codes have helped organizations increase efficiency, reduce operational costs, and in turn increase profits.