82ad790e_and_Merchant_Services_Glossary__Definition
[Term] Card Verification Value (CVV) [Definition] 
The three- or four-digit number typically following the account number, located on the signature panel on the back side of most credit and debit cards, However, CVV numbers on American Express cards appear on the face of the card above the card number.
Credit Card Processing and Merchant Services Glossary
Definition