When and why do we need grub bootloader under Linux!?

[thedhubs]

When and why do we need grub bootloader!?

So here my questions:  why do you use Grub - i do not know much about Grub
Why should /could we use GRUB?

Plz leme know your ideas and thoughts

[Nick H. Supervisor]

  On 06/04/2025 at 09:42, thedhubs said:

When and why do we need grub bootloader!?

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https://en.wikipedia.org/wiki/Bootloader

Also see this: 

GRUB allows me to dual-boot. Windows' BOOTMGR does not as far as I'm aware.

[Ixion]

  On 06/04/2025 at 09:53, Nick H. said:

https://en.wikipedia.org/wiki/Bootloader

Also see this: 

GRUB allows me to dual-boot. Windows' BOOTMGR does not as far as I'm aware.

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Windows bootmanager has allowed dual booting for years, it's not at straightforward to setup as Grub but I used to dual boot Windows and Linux that way even back in the early 2000s

https://www.windowscentral.com/software-apps/windows-11/how-to-create-a-dual-boot-setup-on-windows-11 step by step instructions if you're interested.

[C:Amie]

GRUB is the piece of code that sits between the BIOS completing its power on self test and the startup and initialisation process of the operating system. It's the code that finds the operating system(s) on the disk and performs the handover. They can do this because they understand where the code is that needs to be executed and have the file system drivers necessary to read it (which the BIOS doesn't). They also allow multiple operating systems to exist concurrently on the device. Under Windows the GRUB equivalent was DOS, then NTLDR and finally BootMGR on current releases.

It used to be common that Linux would boot using LILO and not GRUB, but GRUB is newer, better featured and better maintained, so most dists use GRUB.