I'd like to know what the difference is between
shutdown -H (halt the machine) and
shutdown -P (poweroff the machine).
I understand what poweroff means; it's rather self-explanatory. But what exactly is "halt"?
Background: I need to turn off my PC with a terminal-command because otherwise the shutdown/reboot hangs.
I found the command
shutdown -H -P +0 here.
It seems to be combination of the two options and it really works fine.
P.S. I have Lubuntu 18.04.2, 64 bit