What does the last 3 numbers on back of credit card indicate?

Those three numbers are security codes specific to that particular card and used as a reference to determine the legitimacy of, say, an online purchase or telephone transaction. Simply stated, it's an anti-fraud implement.What does the last 3 numbers on back of credit card indicate?
The last 3 numbers on the back of credit cards are security numbers. For example, if someone found your credit card number on the front of the card and tried to use it online, most places ask for the 3 digit security code on the back of the card. If they don't have the card, they won't be able to make a purchase. Just an added step to decrease identity theft.What does the last 3 numbers on back of credit card indicate?
They are a security code. When I order something online, I usually have to enter my credit card number as well as the security code. I guess they want to have an added level of protection - you can't just use the number, must have the actual card in your possession.
C I D = Card identification number
That is your security code. It helps protect credit card fraud in a sense.
It's a security measure
security code