CVC(CardVerificationCode) is an additional code printed on the back of a credit card, also called CVV(CardVerificationValue), which is the verification value of a credit card, and some are called CID, which is a credit card security code or a personal security code. All names refer to the same verification code. Please note that this verification code does not refer to the password of the credit card. Generally speaking, it is possible for domestic credit cards to have passwords, while foreign credit cards do not have passwords. ) the display position is on the back of the credit card, and the top of the signature is displayed in italics. The first four digits are the card number and the last three digits are the verification code.