systemd Basics Part 1 covers the shutdown and reboot commands.

In "systemd Basics Part 1", we'll cover the "systemctl poweroff" and "systemctl reboot" commands. We'll also see how you can still use the old "shutdown" commands for more flexibility with administering your Linux servers. For both present and aspiring Linux systems administrators, learning systemd is an absolute must.

A linux administrator tutorial from beginlinux guru. ... https://www.youtube.com/watch?v=AEvyaObN2g8