What is a Barcode?

A barcode is a method that uses vertical bars of varying thickness and the spaces between them to transfer data automatically and without errors between systems. A barcode is made up of bars of different widths and the spaces between those bars.

Barcodes let you represent information such as a stock code, serial number, or employee code. Entering this information by keyboard is slow and tiring, and it leads to mistakes. To reduce errors and time, barcodes and barcode readers are used instead.

A barcode does not encode the product's code or a product description. It carries only a reference number that identifies the product. The reference number is registered in the system, and detailed product information is kept in the system. When the product information is needed, the reference number gives access to the full record.

For example, a supermarket barcode printed on a product does not contain the price or details. It is a reference number. The product is registered in the supermarket's system against that reference number. Price and other information sit in the system. When product data is requested, the reference number is sent to the system, and the system returns the full product detail. In this model, a price change only requires updating the system.

Barcodes are printed according to rules called barcode symbology, which defines how the bars and spaces are laid out. Barcodes can carry digits 0-9, alphabet characters, and specific special characters (*, -, /, and so on). Several barcode symbologies exist. Some carry digits only; others carry digits plus special characters. From these differences, various barcode standards have emerged. Many barcode formats are in use worldwide today.