Electronic payment systems allow customers to make online payments for purchases. It is a form of direct payment without physical presence using electronic means. Some examples of electronic payment systems include online reservations, bill payments, ticket bookings, shopping, and learning. Common electronic payment methods include smart cards, credit cards, debit cards, e-wallets, and e-cash. A payment gateway is an e-commerce service that authorizes payments for online businesses by encrypting sensitive credit card information to securely pass between customers, merchants and payment processors.