What is the CVV2 code ?

The CVV2 code is an extra security precaution which helps protect you when ordering online. It does this because it helps to prove that you are in possession of the credit card. This protects you against someone stealing your credit card and trying to make purchases because normally they would not have this number.
Visa & MasterCard American Express
The CVV2 code is the 3 digit number on the back or your card as shown: The CVV2 code is the 3 or 4 digit number on the front of your card as shown:
cvv2 cvv2 american express