From Gentoo Wiki
A bootloader is a program that will load bootable items when the system is started.
Depending on the architecture of the machine, several bootloaders are available:
- GRUB - Also known as GRUB Legacy.
- GRUB2 - Reworked version of GRUB. Gentoo's default bootloader on x86 and amd64.
- syslinux - A collection of simple bootloaders for various purposes.
- LILO - A simple boot loader with some advantages over GRUB and GRUB2.
- EFI stub kernel - Using the (U)EFI firmware to function as bootloader.