What are geostationary and polar satellites?

Explanation

Geo-stationary satellite is the satellite which revolves around the Earth with same speed and in the same direction as the Earth rotates.
`R_(E)+h=((GM_(E)T^(2))/(4pi^(2)))^(1//3)" "...(1)`
By substituting the values for the time period, mass and radius of the Earth, in equation (1) h turns out to be 36,000 km. Such satellites are called "geo-stationary satellites", since they appear to be stationary when seen from Earth. INSAT group of satellites that are basically geo-stationary satellites used for the purpose of telecommunication.
A Polar satellite covers a small strip of area from pole to pole during one revolution. In the next revolution it covers a different strip of area. Since the Earth would have moved by a small angle. In this way polar satellites cover he entire surface area of the Earth.