Possessed objects often are used together with a personal identification number (PIN), which is a numeric password. Three common types of authentication are memorized information, biometric devices, and possessed objects. With memorized information, the user enters a word or series of characters that match an entry in the computerís security file. Examples of memorized information are passwords, user IDs, and logon codes. A password is confidential, usually known only by the user and possibly the system administrator. A user ID usually identifies the user, and a logon code identifies an application program. A possessed object is any item the user must carry to access the computer facility. Some examples are keys, badges, and cards.