Understanding the basic computer architecture

Before we can talk about bootloaders, we need to define a few terms that describe the basic computer architecture:

• Bootloader: The bootloader is the first software program that runs when a computer is booted. Its job is to load the Linux kernel and to start the init system.
• Boot manager: When you first power on your computer, a boot manager will present you with a boot menu. If you have multiple operating systems installed, the boot manager will allow you to choose which one to boot. If a Linux distro has multiple kernels installed, the boot manager will allow you to choose which kernel to boot.
• BIOS: The Basic Input/Output System (BIOS) is firmware that resides in a chip on a computer motherboard. It contains the basic instructions that start up a computer. After the computer is started, the BIOS will perform a Power-on Self Test (POST) to verify that the hardware is working properly. Then, the BIOS will start the bootloader...