This satellite orbits at an altitude above 35000 kilometers and has a correspondingly longer orbital period of 24 hours. Because it is orbiting in the same plane as the Earth is rotating (the equatorial plane) and it completes an orbit in the same time the Earth completes a rotation (one day), it appears to remain stationary relative to the Earth's surface. This is the key property of geosynchronous satellites.
Geosynchronous satellites are useful for communication purposes because receivers on the ground - like your satellite TV or radio antennas - don't have to move to track them across the sky. Since geostationary satellites necessarily orbit around the equator, this also explains why satellite TV antennas in the northern hemisphere must face to the south (and to the north in the southern hemisphere).
(Note: Although the ground track of Nilesat 101 appears to form a ring, it's not "orbiting" some point above the Atlantic. I don't presently know how to explain the motion. I suppose if the satellite's orbit is not perfectly
aligned with the equator, as few must be, it will appear to wobble above and below the equatorial plane over the course of each day – and indeed, the same pattern
is exhibited by other geosynchronous satellites.)
For more information about different kind of orbits, including very clear descriptions and diagrams, see these two
pages at NASA's Earth Observatory site.