What bit of a barcode gets scanned?

When a barcode is scanned, the scanner reads the alternating patterns of black and white bars, which represent specific numerical or alphanumeric data encoded within the barcode. The scanner captures the width and spacing of these bars, converting them into a digital signal that corresponds to the encoded information. This data is then processed by a computer system to retrieve product details or inventory information. The entire barcode is scanned, but the unique pattern allows for quick identification of the item.