System Crontab or Root Crontab.
/etc/crontab is the system-wide crontab.
The format of /etc/crontab is like this:
# m h dom mon dow user command
* * * * * someuser echo 'foo'while crontab -e is per user, it’s worth mentioning with no -u the argument the crontab command goes to the current user’s crontab. You can do crontab -e -u <username> to edit a specific user’s crontab.
Notice in a per-user crontab there is no ‘user’ field.
# m h dom mon dow command
* * * * * echo 'foo'
An aspect of crontabs that may be confusing is that root also has its own crontab. e.g. crontab -e -u root will not edit /etc/crontab
In most Linux distros, per-user crontabs are typically stored in the: /var/spool/cron/crontabs/<username> (Vixie-cron).
RHEL-based distributions are stored in /var/spool/cron/<username>. (cronie)
