1. A merchant transaction occurs by a customer placing an order.
2. Merchant forwards transaction details to the payment gateway.
3. The gateway sends info to the merchant's acquiring bank's payment processor.
4. The payment processor forwards the transaction info to the card association.
5. Card association sends response (token) back to the payment processor.
6. Payment processor forwards token to the payment gateway.
7. Payment gateway sends token to merchant as relevant info.
