Credit Card

A credit card is a system of payment named after the small plastic card issued to users of the system. A credit card is different from a debit card in that it does not remove money from the user's account after every transaction. In the case of credit cards, the issuer lends money to the consumer (or the user) to be paid to the merchant. It is also different from a charge card (though this name is sometimes used by the public to describe credit cards), which requires the balance to be paid in full each month. 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.
Source:http://en.wikipedia.org/wiki/Credit_card