A savings card is a card directly associated with a bank account, which is used to deduct payment directly from the savings account. The source of funds is the user's savings deposit. A credit card is a card that can be overdrawn. Cardholders can spend first and then repay within a certain amount. The source of funds is the bank's credit line. A debit card is a card directly associated with a bank account, which is used to deduct payment from a debit account. The source of funds is the user's deposit balance. Savings cards are mainly used for daily consumption and withdrawal, credit cards are mainly used for large consumption and installment payment, and debit cards are mainly used for daily consumption and withdrawal, which has the characteristics of real-time deduction.