Explain what is Meant by Satellites in Geostationary Orbits? What is it Useful for?

-They contain a High Orbit over the Earth's Equator and Orbit every 24 Hours -They will always stay Above on the Same Point on the Earth's Surface, as because Earth will Rotate with them -They are Useful for TV, Telephone or Radio, as they always Sit on the Same Point Above Earth, so its Easy to Point Transmitters and Receivers at them. Also its Stupid Quick.