Geosynchronous

Refers to an orbit (about 22,300 miles above Earth’s surface) with a period equal to one day. A satellite in geosynchronous orbit above Earth's equator will stay over the same point on Earth at all times. Communications satellites are often put in geosynchronous orbits so that satellite dishes on earth can remain pointed at the same point in the sky at all times.

Term applied to any equatorial satellite with an orbital velocity equal to the rotational velocity of the earth. The net effect is that the satellite is virtually motionless with respect to an observer on the ground