The security code of the card is the number printed on the card. The number is not embossed. Form and position vary depending on the card. Some cards have a three-digit number printed at the end of the signature. Some (for example, AMEX cards) have a four-digit number on the front of the card. This number is also called differently. In practice, the following names are used: security code, personal security code, card verification value … Other names are CVV2 for Visa cards or CVV card for Mastercard and Eurocard, as well as security code for AMEX cards.
VISA uses CVV or CVV2, while Master Card uses CVC or CVC2.
It is a three or four-digit product on the back of the card to help secure your payment.
CID (card ID) is a special four-digit number on the front of the American Express card.