Various satellites have been launched over the course of space exploration but a satellite is considered any solar body that orbits another larger body. Many satellites have been launched varying from telescopes to communications satellites to space stations.
Approximately 6600 satellites have been launched, approximately 3600 remain in orbit, and approximately 1000 are still operational. There are man-made satellites orbiting other planets in our solar system too, one at Mercury, three at Mars, and one at Saturn.
One of the most influential Satellites is the Hubble Space Telescope. This telescope is high powered and placed into space to counteract how Gravity and the atmosphere warps images coming into earths Atmosphere.