The password itself is not stored in AD in decryptable form. As I understand it what is stored is a hash of the password and the date/time when the password was set. When a user logging on enters the password that value and the date/time when the password was last set are used to re-calculate the stored hash. if this is the same as the stored hash, the assumption is that the user entered a valid password.
Full Definition of CREDENTIAL. 1. : something that gives a title to credit or confidence; also: qualification 3a. 2. plural: testimonials or certified documents showing that a person is entitled to credit or has a right to exercise official power.
preÂ·reqÂ·uiÂ·site. (prÄ-rÄkâ²wÄ­-zÄ­t) adj. Required or necessary as a prior condition: Competence is prerequisite to promotion. n. Something that is prerequisite, as a course that is required prior to taking an advanced course. prerequisite. (priËËrÉkwÉªzÉªt)