Question

How does a boot loader work?                          

Answer 1

A boot loader is a small program that starts your computer and loads the operating system. When you turn on your computer, the boot loader is the first thing that loads into memory. The boot loader then loads the operating system from the hard drive or another storage device.

Answer 2

When a computer is turned on, the BIOS or UEFI firmware loads the boot loader program from the boot sector of the hard drive into memory. The boot loader then loads the operating system kernel into memory and transfers control to it. The boot loader may also perform other tasks, such as initializing hardware devices and loading additional drivers or system utilities. If multiple operating systems are installed, the boot loader gives users the option to choose which operating system to start.