(GPS terminology)

A receiver that is set up on a known location specifically to collect data for differentially correcting rover files. The base station calculates the error for each satellite and, through differential correction, improves the accuracy of GPS positions collected at unknown locations by a roving GPS receiver.

A transciever device which connects a wireless Ethernet network (typically IEEE 802.11b, aka AirPort) to a wired network. If your wireless-equipped machine (e.g. your laptop) is within range of a base station, you're on the net (if the base station will talk to you, that is).

(P.S. I can't resist pointing out that I'm typing this on a PowerBook connected to the net via a wireless network and just such a base station...)