3. Barcodes

Almost every item that you purchase in a shop has a barcode on it. These look like a series of thick and thin black lines with a series of numbers below.  barcode

Once the barcode is scanned using a barcode reader, the database can find the product details that the barcode relates to. Each type of product will have its own barcode, for example small cans of baked beans will have one barcode, medium cans another and large cans another. These will differ from the barcodes on cans of spaghetti and ravioli.

The barcode contains data about the type of product, size, manufacturer and the country of origin. 

It also contains a check digit, so that the computer can validate that the data has been read in correctly.

The barcode does not contain price. The price is held in the database instead. This makes it easy to change if there are special offers or prices go up. Imagine if the price was part of the barcode. Every time the price changed, you would have to replace all of the packaging.

Once the barcode has been recognised by the database and the price found, the data is sent from the central computer to the till (Electronic Point of Sale - EPOS).


Challenge see if you can find out one extra fact on this topic that we haven't already told you

Click on this link: Barcodes