A signal is sent from station A to the satellite and the satellite amplifies the signal and sends it to station B
The satellite can be used as a repeater, which means that it receives signals from one place on Earth and retransmits them back to another location.
Satellites are also used for navigation purposes, such as GPS (Global Positioning System).
GPS uses satellites to determine your exact position on Earth by measuring how long it takes for radio waves to travel between your device and multiple satellites.
Many weak signals hit the curved dish, they reflect back to the focal point and makes the signal strong