user ID (UID)

The user ID(UID) is a user-specific identifier that can be used to identify each user.

The user ID is a unique identifier that the user uses to log in to a computer's operating system, application programs, databases, networks, services, or to use resources. A logged-in session remains active until the user logs out by logging out. Unlike the password, the user ID can also be known to third parties. To achieve minimum security, the user ID and password are entered during authentication.