How do you explain what the BIOS is to non-Super User?

In a particularly nerdy Facebook status update I mentioned that I had flashed my BIOS. One of my friends asked what the BIOS is.

My question is: How do you explain what the BIOS is and does to a layperson? (Hint: "The BIOS is the basic input/output system" is not going to be accepted as the answer.)

(Of course, the real question is "does she like me?", but I'm not sure there's a site for this :-p )

Usually when I try to explain a technical concept to a non-techie, I revert to Simple English Wikipedia.

"BIOS, in computing, stands for Basic Input/Output System. The BIOS is a computer program embedded on a chip on a computer's motherboard that recognizes and controls various devices that make up the computer. The purpose of the BIOS is to make sure all the things plugged into the computer can work properly"

Okay, the best way to explain it to her is to buy a new upgrade part for your computer, then invite her over to help you install it. Then you'll be able to show her all of the parts inside a PC, show her how to access the BIOS, explain what it does, and maybe order some Chinese food. If you do this right, she'll spend a couple of hours with you, and you should be able to upgrade to a second date without too much effort.

Of course, if she says she's not interested in helping you, you'll at least be able to console yourself with your new PC upgrade.

It's a win-win situation. :-)

For short definitions, I usually use the first sentence or two on Whatis:

BIOS (basic input/output system) is the program a personal computer's microprocessor uses to get the computer system started after you turn it on.