1. Annual fee, credit cards all have annual fees, but some credit cards are exempt from annual fees in the first year, and the annual fees for the following years can be waived if the card reaches a certain level every year; some credit cards do not have annual fees. The annual fee-free policy requires users to pay an annual fee.

2. The longest interest-free period for a credit card is generally 50-56 days. You can enjoy interest-free treatment if you repay in full on the final payment date.

3. Credit cards are not allowed to cash out, but you can withdraw cash appropriately. The amount of cash withdrawal is generally 50% of the credit limit, and a certain handling fee is required for cash withdrawal.

4. A certain amount of penalty interest will be charged for overdue credit card payments.

5. The credit limit of a credit card is not fixed and will be increased or reduced according to the user's usage.