I would like to know different stages of the Bootloading process happening in ubuntu.
Specifically the different stages in GRUB and GRUB2.
Please guide me on this topic.
Wikipedia's GRUB entry has a good overview of how the GRUB boot process works here.
For the differances in GRUB 2 the Ubuntu Help entry is pretty thorough.
The upstream GRUB manual has a section on the various image files, including a discussion of the differences between GRUB Legacy and GRUB 2.