The age range of credit card processing is 18 to 65 years old, and minors and retired employees cannot apply for credit card master cards. Credit card is a credit certificate issued by a commercial bank or credit card company to eligible consumers. Consumers with credit cards can go to special commercial service departments for shopping and spending, and then the bank will settle accounts with merchants and cardholders, and cardholders can overdraw within the prescribed amount and repay the expenses afterwards.