[Techtalk] USB hardware question

[Amanda Babcock]

I'm trying to set up my computer for USB and I'm confused about the 
hardware required.

It doesn't have any USB ports that I'm aware of, but the manual for the
motherboard mentions USB in the part about support for a PS/2 mouse.
Back in 98 or so I bought a no-name USB PCI card, a Kouwell KW-580, and 
installed it but was never able to make it work (not even under Windows).

The USB card is currently not installed, but the machine must be detecting
the host controller on the motherboard because it shows the following
during boot-up (this is a FreeBSD system):

Dec 11 22:34:05 mercury /kernel: uhci0: <VIA 83C572 USB controller> port 0x6100-0x611f irq 11 at device 7.2 on pci0
Dec 11 22:34:05 mercury /kernel: usb0: <VIA 83C572 USB controller> on uhci0
Dec 11 22:34:05 mercury /kernel: usb0: USB revision 1.0

(Incidentally, the motherboard manual does not show a "VIA 83C572" anywhere
in the diagram...)

So, my question is: do I *need* a USB card, or can I plug stuff into the 
controller?  What's a USB controller anyway?  Am having trouble finding a 
basic "What is USB" page out there.  Plenty of info on required drivers 
and kernel configs for both Linux and FreeBSD, but nothing on "what the 
heck is USB anyway".

Amanda