Security questions are a set of questions that may be presented to a user in the context of an authentication process. They should generally be questions which the user can answer and easily remember, but which others will likely not know and not be able to easily deduce.
Security questions are also sometimes referred to as knowledge based authentication.
Hitachi ID Password Manager includes a mechanism to enroll security questions from users. It can use security questions, alone or in combination with other authentication factors to authenticate users who may have forgotten their password