CVV2 is a number printed in the signature area of Visa/MasterCard card. It is located in the 3 digits after the credit card number. The last three digits we usually see on the back of a credit card are actually CVV2, not CVV code.
The reason why a CVV code is added on the back of the card is to confirm that the card is really in the cardholder's own hand. So when you swipe your card outside, be careful not to let people see it easily, especially to write down three digits, so as not to steal it together with the validity period of the card number and then steal it online.
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The CVV code is equivalent to the ID card of a credit card and is mainly used to confirm the transaction. After obtaining the credit card, you will use the security code for key operations such as card opening and activation. In addition, in some websites or telephone transactions, you can complete the transaction by providing the account number, expiration date and security code, and you don't need to provide the password, so the CVV code is as important as the credit card password. Don't tell these key information to others casually.
The cvv2 code is a number printed in the signature area of the Visa/Master Card card. The three digits behind the credit card number can generally be seen on the back of the credit card. It's actually cvv2, not cvv code. Check Cvv2 and cvc2 when trading over the counter or manually.
VISA card CVV and MC card CVC are 3-digit or 4-digit numbers generated by card number, expiration date and service constraint code, which are basically in the card magnetic stripe and 2-track user-defined data area. CVV and CVC are generated in the same way, but with different names.
Baidu Encyclopedia -CVV Code