GRUB 2 is the next generation of the GRand Unified Bootloader (GRUB). Ubuntu has used GRUB 2 as the boot loader since 9.10 (Karmic Koala). Commonly referred to as simply "GRUB".
What questions should have this tag?:
- Questions on how to edit, repair, or troubleshoot GRUB 2
- Questions on how GRUB 2 works
Some basic definitions:
Bootloader - This is a program which loads the operating system (OS) or other software, after POST (power-on self-test).
Boot Record - Contains information on which OS(s)/program(s) to "boot", and information about where these are located.
Brief introduction to the subject:
From the Ubuntu Wiki page for GRUB 2:
GRUB 2's major improvements over the original GRUB include:
- Scripting support including conditional statements and functions
- Dynamic module loading
- Rescue mode
- Custom Menus
- Graphical boot menu support and improved splash capability
- Boot live CD ISO images directly from hard drive
- New configuration file structure
- Non-x86 platform support (such as PowerPC)
- Universal support for UUIDs (not just Ubuntu)