Cron vs Anacron

The key difference between cron and anacron is what happens when the computer is off. Cron skips any jobs that were scheduled while the system was down — they're simply missed. Anacron tracks when jobs last ran and executes missed jobs when the system comes back up.

Cron: precise timing (minute-level), requires the system to be running at the scheduled time, works with any frequency. Anacron: daily or less frequent only (no minute/hour scheduling), catches up on missed runs, designed for machines that aren't always on (laptops, desktops).

Use cron for: servers that run 24/7, jobs that need precise timing (e.g., every 5 minutes), sub-daily schedules. Use anacron for: laptops/desktops, daily/weekly/monthly maintenance tasks, situations where it's more important that a job runs eventually than that it runs at an exact time. Many Linux distributions use anacron for /etc/cron.daily/, /etc/cron.weekly/, and /etc/cron.monthly/ scripts.