On Visa, MasterCard and Discover cards, the CVV2 value is the 3 digit number located in the signature area on the back of your credit card, just to the right of your account number. On American Express cards, the CVV2 value is the 4 digit number located on the front of your credit card, just above and to the right of your account number.

AVS: stands for Address Verification System. Validates the address of the credit card holder when street address and zip/postal code is provided.