telinit — Change SysV runlevel
telinit [OPTIONS...]  {COMMAND} 
telinit may be used to change the SysV system runlevel. Since the concept of SysV runlevels is obsolete the runlevel requests will be transparently translated into systemd unit activation requests.
The following options are understood:
The following commands are understood:
Power-off the machine. This is translated into
        an activation request for poweroff.target
        and is equivalent to systemctl
        poweroff.
Reboot the machine. This is translated into an
        activation request for reboot.target and
        is equivalent to systemctl
        reboot.
Change the SysV runlevel. This is translated
        into an activation request for
        runlevel2.target,
        runlevel3.target, ... and is equivalent
        to systemctl isolate runlevel2.target,
        systemctl isolate runlevel3.target,
        ...
Change into system rescue mode. This is
        translated into an activation request for
        rescue.target and is equivalent to
        systemctl rescue.
Reload daemon configuration. This is equivalent to systemctl daemon-reload.
Serialize state, reexecute daemon and deserialize state again. This is equivalent to systemctl daemon-reexec.
This is a legacy command available for compatibility only. It should not be used anymore, as the concept of runlevels is obsolete.