How do I differentiate between a QR code and a barcode in the context of the ATM?
For a sale, the operator's QR code identifies the deposit address for the selected cryptocurrency and network. For a purchase, your wallet QR code identifies your receiving address. These addresses have different purposes.
A sale barcode is used for cash collection after the operator's status confirms that the transaction is ready, at a compatible working ATM. Keep the collection barcode private.