That's the magnetic stripe. When a cardholder uses a credit card to make a large amount of consumption, the card-issuing bank will pay the merchant the consumption funds of the goods (or services) purchased by the cardholder in one lump sum, and deduct the consumption funds from the cardholder's credit card account in stages according to the cardholder's application, and the cardholder will repay the business according to the monthly recorded amount.

in the past, credit card installment mainly included bill installment and single consumption installment, and banks usually charged corresponding handling fees according to the number of installments. Whether it is bill installment or single consumption installment, the premise is to generate consumption behavior first, and then the bank will set up the installment repayment of the generated credit loan. Extended information

Criminals or criminal groups pass off fake or invalid cards (expired, lost and invalid, damaged tapes, etc.) as genuine cards for consumption, directly deceiving merchants or card issuers.

improper card keeping/handling (expired credit cards with invalid tapes are not destroyed, or lost credit cards are not immediately invalidated, etc.), and personal identity information is inadvertently stolen or defrauded. In order to avoid such problems, citizens should not easily provide personal identification information, and it is best not to entrust others to handle credit cards.

Baidu encyclopedia-credit card