Boot code

Boot code is a set of "instructions" that are run by a computer when it is starting up. The boot code helps the computer prepare the system for loading and running an operating system, but boot code itself is usually not operating system specific. Boot code may run from a hard drive or even directly from a computer CPU (Central Processing Unit) if it's integrated into the silicon. Without boot code, a computer would likely not boot up correctly, if at all.

BIOS, Boot, Bootloader, Firmware, MBR, Operating system terms, POST, UEFI