A lock-out function is a security mechanism in IAM or access management that denies access to a system or user account after a certain number of failed login attempts. The idea is to prevent brute force attacks in which an intruder tries to gain access by systematically trying many possible passwords.
There are all kinds of implementations of such mechanisms. Some lock out a user only for seconds after a threshold of failed login attempts is being reached while other progressively increase the time period. Some are silent, others notify the user. Some may at some point lock out the user completely, forcing them to reset their password or even having to seek for assistance from an administrator.
In any case, the lock-out functionality needs to be a part of an overall cyber security concept to notice and mitigate unauthorized access attempts.
