A barcode is a pattern of parallel lines of different widths printed on a machine-readable product. A barcode is basically some information kept in a visual pattern that only a machine can read. The pattern of black and white mixed bars that we see in the barcodes follows an algorithm. Barcodes usually contain product information such as: product price and weight , date of manufacture and expiration (expiration) , manufacturer's name, etc. Internationally, the barcodes of each product are different. However, barcodes are used for many other purposes besides products.