A debit card is an ISO 7810 card which physically resembles a credit card, and, like a credit card, is used as an alternative to cash when making purchases. However, when purchases are made with a debit card, the funds are withdrawn directly from the purchaser's current/checking or savings account at a bank.

A credit card system is a type of retail transaction settlement and credit system, named after the small plastic card issued to users of the system. A credit card is different from a debit card in that the credit card issuer lends the consumer money rather than having the money removed from an account. It is also different from a charge card (though this name is often used to describe credit cards by the public) in that charge cards do not extend the user credit -- the charges must be paid each month in full. In contrast, a credit card allows the consumer to 'revolve' their balance, at the cost of having interest charged. Most credit cards are the same shape and size, as specified by the ISO 7810 standard.