voluntary, intentional, deliberate, willing mean done or brought about of one's own will. voluntary implies freedom and spontaneity of choice or action without external compulsion. a voluntary confession; intentional stresses an awareness of an end to be achieved. the intentional concealment of vital information deliberate implies full consciousness of the nature of one's act and its consequences. deliberate acts of sabotage
PAM is a framework that assists applications in performing what I'll call authentication-related activities. The core pieces of PAM are a library (libpam) and a collection of PAM modules, which are dynamically linked libraries (.so) files in the folder /lib/security.
Two-factor authentication (also known as 2FA) is a method of confirming a user's claimed identity by utilizing a combination of two different components. Two-factor authentication is a type of multi-factor authentication.