A debit card (also known as a bank card or check card) is a plastic card that provides an alternative payment method to cash when making purchases. Functionally, it can be called an electronic cheque, as the funds are withdrawn directly from either the bank account or from the remaining balance on the card.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.

The use of debit cards has become widespread 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, and unlike credit cards the funds are transferred from the bearer's bank account instead of having the bearer to pay back on a later date.
Debit cards can also allow for instant withdrawal of cash, 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.