Yep (BTW, that is not a stupid question).
We recently purchased a Yukon XL ---- salesperson kept telling us we wanted the stabilitrak, but could never answer our reasons why we would or even what it was... Just kept saying, extra $1000 for it and we would want it.. HUH ???
So I did some research of our own then, and what I found out sounded similar to what was posted here, but I wasn't sure