Difference between payment aid & smart payment gateway

Friends, does anyone know the difference between a payment aid and a smart payment gateway?

Hi Ayla,
Actually, there’re some differences but most important one is
that you don’t need an electronic trust symbol to use the payment, or to set up the interface, but to set up a smart payment gateway, you must have a trust symbol. I linked to one of the sites I know in that field. You can go and see yourself.