(1) Ground based. From the Greek word for "earth." See geostationary, geodetic coordinates, geocaching and geotagging.|
(2) (Geostationary Earth Orbit) A communications satellite in orbit 22,282 miles above the equator. At this orbit, it travels at the same speed as the earth's rotation, thus appearing stationary. GEOs are excellent for TV broadcasting, but produce distracting, half-second delays in interactive voice conversations, because of the long round trip from earth and back. LEOs and MEOs, which are closer to the earth, are being deployed for interactive services. See LEO and MEO.
GEOs rotate at earth speed and thus appear stationary. LEOs and MEOs are closer to earth and revolve around the planet.