cron job
also: crontab, scheduled task, cron entry
A scheduled task that runs automatically at specified intervals on a Linux system, managed by the cron daemon. Users define recurring jobs in a configuration file called a crontab.
A cron job is an automated task executed by the crond daemon at predefined times or intervals. It's ideal for repetitive administrative work like backups, log rotation, or cleanup scripts that need to run without manual intervention.
Jobs are defined in a crontab (cron table) file using a simple syntax with five time fields (minute, hour, day of month, month, day of week) followed by the command to execute. For example, 0 2 * * * /usr/local/bin/backup.sh runs a backup script daily at 2:00 AM.
Each user can have their own crontab accessed via crontab -e, and the system administrator manages global cron jobs in /etc/cron.d/ and related directories. The cron daemon checks schedules every minute and executes matching jobs as configured.