is an anti-fraud security feature to help
verify that you are in possession of your credit card.
For Visa/Mastercard, the three-digit CVV number is
printed on the signature panel on the back of the card immediately
after the card's account number
For American Express, the four-digit CVV number is printed
on the front of the card above the card accountnumber.
A 3-digit number in reverse italics
on the back of your credit card
A 4-digit number on the front, just
above your credit card number