Both cron jobs and 'at' jobs are used for job scheduling in Unix-like operating systems, but they differ in foundational elements and functionality. ​​Cron jobs are recurring and can be scheduled to run repeatedly, like every minute, hour, day of week, day of month, week, or month. They are typically used for tasks that need to be executed on a regular basis like system maintenance, backups, or data synchronization. Cron jobs are managed using the crontab command, which allows crontab entries and cron jobs to be created, modified, and deleted based on the user account. Cron jobs are defined in a crontab file that contains the schedule and command to be executed. Cron jobs are stored in the system's cron directories and executed by the cron daemon at the scheduled times. Unlike cron jobs, 'at' jobs are designed for one-time, delayed job scheduling. They make it possible to schedule a task to be executed at a specific time in the future, rather than on a recurring basis. 'at' jobs are useful for performing a task once or at a specific moment in the future, like running a shell script at a particular date and time or executing a command after a delay. 'at' jobs are stored in the system's 'at' spool directory and executed by the 'at' daemon to run at the scheduled time. Once the job is complete, notifications are sent to the current user with the output of the job. Compare cron job scheduling and at jobs with ActiveBatch for workload automation.