What is a geostationary satellite?

The satellite which appears at rest when observed from any location of earth is called geostationary satellite. Following conditions must be fulfilled by a satellite to be geostationary:

1. The time period of the satellite around the earth must be equal to the rotational period of the earth about its own axis (i.e. 24 hours).
2. The direction of motion of the satellite must be same as that of the earth.
3. The height of geostationary satellite from earth’s surface must be about 36000 km.
4. The plane of the orbit of that satellite should be in the same plane as the equatorial plane.
5. The centre of the circle formed by the motion of the satellite and the earth’s centre should also be coincident.