system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What is the computer's BIOS and what does it do?

Thanks!
gpt
**B**asic **I**nput **O**utput **S**ystem. 

It's the software installed onto a chip on the motherboard that interprets all the hardware signals of the various parts of a computer, identifies those parts, checks everything is order and starts up more complex software (Usually an operating system like Windows) that might make use of those parts.