The Card Security Code (CSC), sometimes called Card Verification Value (CVV or CV2), Card Verification Value Code (CVVC), Card Verification Code (CVC), or Verification Code (V-Code or V Code) is a security feature for credit or debit card transactions, giving increased protection against credit card fraud.
Mastercard
Visa
American Express
The CVC should not be confused with PIN codes such as MasterCard SecureCode or Visa Verified by Visa. These codes are not printed or embedded in the card but are entered at the time of transaction using a keypad.
More information can be found on Wikipedia - Card Security Code.
