reboot restarts the machine. On a systemd system it is a convenience symlink to systemctl reboot, which asks systemd to shut down services cleanly and then trigger a kernel-level reboot.
sudo reboot
sudo systemctl reboot # equivalent
sudo reboot -f # skip systemd, force immediate reboot
Related commands: shutdown -r now does the same via the traditional interface; halt powers down without rebooting; poweroff explicitly turns off the machine. All of these ultimately go through systemd on modern distributions.
Discussed in:
- Chapter 13: System Services and systemd · systemctl: Controlling Units
