A credit card is a system of payment named after the small plastic card issued to users of the system. In the case of credit cards, the issuer lends money to the consumer (or the user) to be paid later to the merchant. It is different from a charge card, 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 issued by local banks or credit unions, and are the same shape and size, as specified by the ISO 7810 standard.

A Debit card is a plastic card which provides an alternative payment method to cash when making purchases. Its functionality is more similar to writing a cheque as the funds are withdrawn directly from either the bank account (often referred to as a cheque card), or from the remaining balance on the card. In some cases, the cards are designed exclusively for use on the Internet, and so there is no physical card.Säkra kortbetalningar på Internet | Nordea.see-kort

The use of debit cards has become wide-spread in many countries and has overtaken the cheque, and in some instances cash transactions by volume. Like credit cards, debit cards are used widely for telephone and Internet purchases. This may cause inconvenient delays at peak shopping times (e.g., the last shopping day before Christmas), caused when the volume of transactions overloads the bank networks.

In some countries the debit card is multipurpose, acting as the ATM card for withdrawing cash and as a cheque guarantee card. Merchants can also offer "cashback"/"cashout" facilities to customers, where a customer can withdraw cash along with their purchase.

Credit card debt is an example of unsecured consumer debt, accessed through ISO 7810 plastic credit cards.

Debt results when a client of a credit card company purchases an item or service through the card system. Debt accumulates and increases via interest and penalties when the consumer does not pay the company for the money he or she has spent.

The results of not paying this debt on time are that the company will charge a late payment penalty (generally in the US from $10 to $40) and report the late payment to credit rating agencies. Being late on a payment is sometimes referred to as being in "default". The late payment penalty itself increases the amount of debt the consumer has.

When a consumer has been late on a payment, it is possible that other creditors, even creditors the consumer was not late in paying, may increase the interest rates the consumer is paying. This practice is called universal default.

Credit card fraud is a wide-ranging term for theft and fraud committed using a credit card or any similar payment mechanism as a fraudulent source of funds in a transaction. The purpose may be to obtain goods without paying, or to obtain unauthorized funds from an account. Credit card fraud is also an adjunct to identity theft.

The cost of credit card fraud reaches into billions of dollars annually. In 2006, fraud in the United Kingdom alone was estimated at £428 million, or US$750-830 million at prevailing 2006 exchange rates.USDGBP=X: Basic Chart for USD to GBP ? Yahoo! Finance