The bar code is like a secret code used to represent the value of the things we buy from the store, the item has a bar code reader to use cashier staff bar codes to decode and send mum to a computer.
A bar code is a code that represents the value of the goods when we buy a product from a store that has a barcode reader, barcode cashier is used to decode and send any information to the computer.
Bar code is a code that represents the value of things when we buy from the store goods bar code cashier will use bar code reader to decipher and transmit the point to the computer.