I remember the days when we go to a supermarket and go to the cashier, the every transactions are really time consuming. It is because the cashier personnel needs to type the price of each product to have them computed. But now, every transactions are much faster because they already have barcode scanner that lets the cashier personnel compute faster. Just by letting the barcode scanner scan the barcodes of each product, the counter already knows every products price making it easier and faster to compute.