Halt purpose: What does "you can perform low level maintenance" mean?

About halt in Linux in these places: * [What is the difference between the shutdown, halt and reboot commands?](https://superuser.com/a/236912/1024056) * [Understanding Shutdown, Poweroff, Halt and Reboot Commands in Linux](https://www.tecmint.com/shutdown-poweroff-halt-and-reboot-commands-in-linux/) * [What is halt command in Linux?](https://frameboxxindore.com/other/what-is-halt-command-in-linux.html) Indicate the following: halt is usually to get to a state where you can perform low level maintenance. and You can use it to get the system to a state where you can perform low level maintenance. Therefore: What does _"you can perform low level maintenance"_ mean? Some examples/scenarios to understand would be valuable. I want to know what is possible to do without the OS running and the PC with running (therefore electricity is available)