system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 how is bios installed on a motherboard?
gpt
There are special memory chips on the motherboard that contain the BIOS.  In ancient times, these were actual ROMs, read-only memory chips.  That's too hard to maintain, so today most mobos use flash memory, like in a USB drive or camera card, to store the BIOS.  That way you can do a firmware update with a special program rather than screwdrivers.