You might think that from the name of the link, but the page fails to
live up to its promise. Some quotations:
"BIOS lives inside a chip on your computers motherboard. Inside the
BIOS, is a small section called “MBR”, which stands for “Master Boot
Record” and is often called “Boot record” or “Boot Sector” or
something like it."
"The BIOS/MBR is a TINY slice at the BEGINNING of your hard disk that
gets run as soon as you startup your computer."
"If you must have the improved UEFI/GPT, then either buy a new computer
(easier) or check if your existing computer is compatible with
UEFI/GPT, and have fun trying to convert it.