cvc means credit card security code. The full name of CardSecurityCode is the security code that credit cards need when conducting online or telephone transactions. The way to generate cvc is that the bank extracts the card account number, validity period and service code, arranges them and calculates them by the bank's own algorithm. The cvc code is displayed on the back of the credit card. The last three digits in italics above the signature are the verification code for commercial banks to ensure the security of credit card passwords, and the first four digits are generally the card number.