GRUB is the GRand Unified Bootloader, a BootLoader that can be used to boot most operating systems.
GRUB provides a user the choice to boot one of multiple operating systems installed on a computer or select a specific kernel configuration available on a particular operating system's partitions.
GRUB was initially developed by Erich Boleyn as part of work on booting the operating system GNU/Hurd, developed by the Free Software Foundation.
