The Grand Unified Boot loader is a very cool way for any machine to boot up. Once a machine
powers on it tends to do basic power on self tests. This is called the POST stage and then
a machine will attempt to boot something. Anything. BIOS would just go looking into the
very first region of a disk drive for software. The UEFI process is way more complex but
also will go looking for a place to find software to run. That is where the boot loader will
happen. The GRUB boot loader will locate the disk device and filesystem with Devuan Linux
stored on it. A discussion about the initial ram disk and Linux kernel would fill a whole
volume and we can not go there now. Just be happy that GRUB is being installed and setup
for you.
