- All right, let me give you an overview,
of everything that's involved in the boot procedure.
Booting starts with either BIOS or UEFI,
where BIOS is the old standard
and UEFI is a new standard.
So from BIOS or UEFI also referred to as the firmware,
you are going to find a disk.
And next on disk you will find the next part.
That's the Grub2 Boot Loader.
This grub2 boot loader,
is responsible for loading the kernel.
And this kernel needs access to drivers.
And that is why the kernel comes together,
with the initramFS,
sometimes also referred to as the initRD.
This initramFS is created while you install your system
and it contains all the drivers,
for the heardware that was detected,
upon the insulation procedure.
And next one, when kernel in initramFS are loaded,
you are going to get into System D,
that is a service manager,
that is taking care of everything else.
And once System D has gone through,
the different boot phases,
you'll get a shell from the shell you can log in
and that's what you need to keep in mind while booting,
because for troubleshooting it's pretty important,
that you are capable of identifying,
where exactly it is going wrong
and we are going to analyze that.
But this is the big picture.