What is security code frequently asked during creating an apple id

Security code for a credit card? Or somewhere else

All credit and debit cards have a Security code on the back, or front. it is a three, or four, digit number that sets your card apart. the reason the Security code is important is so that identity thieves cannot hack your card info with just the 16 digit card number on the front and it also allows you to purchase things without swiping and putting in a pin such as for online items from iTunes and other sites. Visa, mastercard, and Discover card are the brands that have a 3 digit number on the back right hand side by the end of the signature line. American Express (AmEx) is the only card company that uses a 4 digit number located on the front above the 16 digit card number.