As I understand it, The key bits of data are in the QR code, they are just encoded as a URL - a highly structured URL that point of sale systems can decode without visiting the URL.
Doing it this way means the QR code is directly usable by consumers to get to a product info / marketing page, and directly usable by the POS systems.
Doing it this way means the QR code is directly usable by consumers to get to a product info / marketing page, and directly usable by the POS systems.
Edit: I looked it up. An example URL:
https://example.com/01/09521207311511/21/1234ABDE1235
01 is a marker before the traditional barcode.
21 is a marker before the serial number.
There seems to be many other codes like 17 (expiry date) and 10 (batch number).