What do 4-digit pin means?

A 4-digit PIN (Personal Identification Number) is a numeric code typically used for authentication and security purposes, such as accessing bank accounts, mobile devices, or secure systems. It usually consists of four digits, providing a balance between ease of use and security. Users are often advised to choose a PIN that is not easily guessable, such as avoiding birthdays or common sequences. The primary function of a PIN is to verify the identity of the user and protect sensitive information.