CCV stands for Credit Card Validation (or Verification) Value.
The CCV is a 3 or 4 digit code embossed or imprinted on the reverse side of Visa, MasterCard and Discover cards. This is an extra security measure to ensure that you have access or physical possession of the credit card itself in order to use the CCV code. For details on where to find your CCV code, please see the image above.
VISA, MasterCard, Discover
The CCV code is the last 3 digits after the credit card number on the back of the card in the signature area. If your card does not have a CCV code or you cannot read the CCV code, please contact your credit card issuer.