An access point lets wireless PCs with wireless cards access the wired LAN the AP is on. (I think Beep said this.) A wireless hub is an AP plus an ethernet hub plus a cable (or ADSL) modem in the one box.

You can use an AP to extend a WLAN, but you need *two* APs: the first is in range of the original WLAN, then you run a cable to the second AP to create a second WLAN. I doubt your house is big enough to need this! :-)

Wade.