Credit card is a non-cash transaction payment method. It does not encourage depositing cash in advance, implements consumption first and repay later, and enjoys an interest-free repayment period. Cardholders can decide how to repay in installments, but there is a minimum repayment amount requirement. A popular understanding is that a credit card is a small credit payment tool provided by banks to users to consume first and repay later. It can be overdrafted. Moreover, this kind of overdraft consumption enjoys an interest-free period of 20 to 56 days; as long as the repayment can be made on time, no interest will be charged. At the same time, even if there is no money on the credit card, you can withdraw cash from the bank, as long as the repayment period does not exceed 60 days. Because the credit card has this overdraft function, the credit card at this time actually becomes a lending bank. Tracing back to its origins, the earliest credit cards were indeed issued by merchants to customers in order to sell goods on credit, which was equivalent to the accounting book that the owner of the cigarette shop at the door of the community was willing to owe.