The two cards are domestic cards and overseas cards respectively. There is no distinction between primary and secondary cards. Both can be used, but they are used in different places.

One is a UnionPay card, which is used domestically, and the other is a Visa card, which is used abroad. Generally, just use a UnionPay card. The limits of the two cards are interoperable.

Credit card is a non-cash payment method and a simple credit service. A credit card is generally a plastic card with a length of 85.60 mm, a width of 53.98 mm, and a thickness of 1 mm. It is issued to the cardholder by the bank or credit card company based on the user's creditworthiness and financial resources. The cardholder does not need to pay cash when using the credit card to make purchases. Make further repayments. Except for some credit cards combined with debit cards, general credit cards are different from debit cards and ATM cards in that credit cards will not directly deduct funds from the user's account.

Credit cards are issued by commercial banks to individuals and organizations. They can use them to shop and consume with specially appointed organizations and deposit and withdraw cash from banks. They are special carrier cards with consumer credit. They are in the form of a card with the card issuing number printed on the front. Cards with bank name, validity period, number, cardholder name, etc., and a magnetic stripe and signature strip on the back.

A real credit card has the following characteristics: it is not encouraged to deposit cash in advance, consume first and repay later, enjoys an interest-free payment period, can repay in installments independently (with a minimum repayment amount), join VISA, MASTER Wait for international credit card organizations to make it universally applicable.