“What utility do practically all Linux users use–regardless of
their job or expertise? A boot loader. In this article, see how a
boot loader works, meet two popular loaders–LILO (LInux LOader)
and GNU GRUB (GRand Unified Boot loader)–and review the pros and
cons of each.“Most simply, a boot loader loads the operating system. When
your machine loads its operating system, the BIOS reads the first
512 bytes of your bootable media (which is known as the master boot
record, or MBR). You can store the boot record of only one
operating system in a single MBR, so a problem becomes apparent
when you require multiple operating systems. Hence the need for
more flexible boot loaders…”