"You're looking at new systems, or installing Linux on a box
that used to run a different OS, and you're wondering if all the
components--video, modem, Ethernet, sound--will work on Linux. The
vendors can't, or won't, tell you if their products will work on
Linux. You need to know what the chipsets are, to find out if there
are Linux drivers.
"Alternatively, you want to know what components are installed
inside a computer, and you don't feel like hauling the thing out,
popping the case open, and tearing it apart..."