In windows safe mode is a startup option where the OS loads with minimal
drivers and backround programs. Its used for system diagnosis. If a
system has problems and works ok in safe mode that indicates the problem
has to do with third party software. If it fails to boot, its an
indication that the system has problems. Its a nice diagnostic tool. I'm
not aware of anything similar in Linux, but if there is something like
this, I would love to learn about it.