Restart PC safely if your distro crashes

It's weird, but in GNU / Linux we also have our impending PC crashes and there is a very simple method to safely restart it so forget about the button Reset.

We press the keys:

Alt + PrintPantall

And we become an octopus, consecutively typing the following key combination:

RSEIUB

the combination also works:

TRAVELS

But what exactly does this do?

R Returns control to the keyboard.
S Synchronize.
E Send the term signal to the processes.
I Send the kill signal to the processes.
U Unmount the file systems.
B Restart the system.