Scheduling
scheduling recurring jobs with cron & anacron, and one-off jobs with at & batch.

 

Logging
configuring and using syslodg, journald, logger, logrotate & dmesg.

 

Patching
installing, patching & upgrading software with rpm, yum & dnf.

 

Getting help
getting help with man, apropos, whatis, which, whereis, fc, history & locate.