E-payment refers to electronic payments, a subset of e-commerce transactions, for buying or selling goods and services online. There are several types of e-payment systems, including e-cash, micro payments, debit/credit cards, smart cards, peer-to-peer payments, and business-to-business and business-to-customer transactions. Debit cards provide electronic access to a user's bank account for withdrawals or purchases, while credit cards allow borrowing and are commonly used due to convenience. Smart cards contain information like account details and can be used for phone calls, payments, and other applications. E-payment is growing in usage and acceptance due to improvements in security and convenience.