What purpose does Lastlog serve in a UNIX/Linux system?

The Lastlog command in a UNIX/Linux system is designed to keep track of the most recent login time for each user. It records the last time each user successfully logged into the system, allowing administrators to see when users were last active. This information can be useful for security auditing, user management, and monitoring system access.

Monitoring last login times helps in identifying inactive accounts or potential security issues, as users who have not logged in for an extended period may require attention for maintenance or deactivation. The Lastlog data typically includes the username, login time, and the terminal from which the user logged in, providing a comprehensive view of user activity related to logins.