The GeoPort is a small, round jack on the back of some older Macintosh computers.
It is easily confused with a regular modem or printer port and in fact, can be used as an additional modem or printer port. There is one minute difference, however; the presence of an additional pinhole -- a hole where it gets its power -- is what makes the port a GeoPort.
GeoPort modems are also much cheaper than a traditional high-speed fax/modem -- prices can be slashed by nearly a half.
One major device that can be connected to the GeoPort is the GeoPort Telecom Adapter.