What is a PIN number?
A personal identification number (PIN) is a numeric or alphanumeric number that is commonly used as a password or as a code to identify users of a computer system. It serves as a form of authentication and identification. Many places that use a PIN code are ATM machines or in Europe, mobile SIM cards. A PIN code is often used with a card or other form of additional payment. Additional uses of PINs include government authentication with citizens, enterprise authorization with employees, and computer authentication with users.