If a job needs to be carried out, cron spools it and does the work. The spooler for cron is located here. The cron spool contains the queue of work to be done and is occupied while the computer is doing or preparing to do the work. Once the job is finished, the cron spooler is emptied and waits for the next scheduled job to be placed in the spooler. You do not need to have root privileges to schedule a cron job, however you must have root privileges to schedule a cron job that affects the system.
Many system administrators reserve cron for their own use.
Alternately, as the system administrator, you can choose to allow or deny cron privileges to specific individuals by creating cron configuration files. If an allow file exists, only users listed in the file may have access to cron . If a deny file exists, everyone except the listed users may use cron . Normally, if neither file exists, only the super user can use cron . For security reasons, this is typically how cron is configured.