Crucial to the operation of everything from Amazon.com and every other ecommerce site, right down to your local dairy, a Payment gateway is a service authorizing payments between buyers and sellers. In some cases, the Payment Gateway brokers the transaction between a card holder’s financial services provider (by reading their card information) and the seller of goods (the merchant), facilitating the transfer of customer information to allow for processing a payment. For online services, cards are not required, though the numbers often are. Payment Gateways are available from a wide variety of providers, prominent among them Google Wallet, PayPal, Apple Pay and Amazon Pay.