How are artificial satellites useful in communication?

Artificial satellites are equipped with transponders (a device for receiving and transmitting radio signal), radio mete, solar panels and necessary fuel. These satellites receive signals from the earth-station and sent to another earth-station. The signals are electromagnetic waves so they don’t get destroyed. The transmitting station sent a signal called uplink and satellite after receiving sent the signal to another station called downlink. Here is a beautiful diagram showing communication between two base station:-