PIN

A Personal identification number ( also known as “PIN” ) is a password composed by numbers that authenticate the identity of an user in financial and non-financial systems.
A private PIN is used often with a public user identifier. Usually, PIN is a confidential number.
When the Pin number entered by a user matches with the number in the system, The user gain access. We can’t personally identify a User from his PIN.
PIN can be used in ATM or POS but also as a door access, internet transaction,or log in to a restricted system. It doesn’t always have to be associated with a card.