In Brief: The CVV (Card Verification Value) - Understanding the Three Digits Behind the Card
A CVV, or Card Verification Value in English, is a sequence of 3-4 numbers designed to authenticate the cardholder in a transaction. Typically, in credit cards like Visa and Mastercard, the CVV is a 3-digit number located on the back of the card.
For American Express credit cards, the CVV can be entered from either the back of the card or the 4-digit number on the front.