A program scheduling utility is used in operating systems
Cron is the utility used to execute jobs at specified times.
These jobs are known as cronjobs.
Crontab is the file that contains the list of jobs that will be executed at the specified times by the Cron utility.
The crontab -e command is used to add a new job to be executed at a specified time by the Cron utility.
Each job is executed in the following time format:
* * * * * commands/script to execute