satellite & types

WHAT IS SATELLITE?

 A Satellite is a solid object which revolves around some heavenly body due to the effect of gravitational forces which are mutual in nature.
We can categorize satellites in two types, namely Passive Satellites and Active satellites.
 Passive satellites are not like active satellites. Even a moon can be a passive satellite. Thus passive satellites are relay stations in space. A passive satellite can be further subdivided into two types, namely Natural satellites and artificial satellites. A moon is a natural satellite of earth. But spherical balloon with metal coated plastic serve as artificial satellites. Active satellites are complicated structures having a processing equipment called Transponder which is very vital for functioning of the satellite. These transponders serve dual purpose i.e. provides amplification of the incoming signal and performs the frequency translation of the incoming signal to avoid interference between the two signals.