GNU GRUB (or just GRUB) is a boot loader package that supports multiple operating systems on a computer. During boot-up, the user can select the operating system to run. GNU GRUB is based on an earlier multiboot package, GRUB (GRand Unified Bootloader). GRUB is most often used on Unix-like systems, including GNU, Linux and Solaris.
Some features of GRUB:
- It can support an unlimited number of boot entries.
- GRUB is dynamically configurable, which means that users can make changes during boot-up.
- GRUB can install to and run from any device, including hard drives, floppy disks, DVDs, CD-ROMs and USB drives.
- It can decompress operating systems before launching them.
- It can load operating systems from various locations, including networks.
- It doesn't need to be re-written each time a configuration file is changed.
- There are implementations that support Windows and DOS.
- The command interface is interactive.