In astonomy, a satellite is any body that orbits a larger celestial body. There are numerous examples of natural satellites, usually moons orbiting planets. Artificial satellites are man-made satellites that are intentionally sent into space to orbit a celestial body, usually the Earth. The telecommunications industry utilizes satellites to enable a global communication network for telephone, television, internet, and GPS use. They are mostly made of metal and lightweight polymers to try to minimize weight during launch. Most importantly, they must be able to withstand the cold temperatures of space.
Satellites work by orbiting the planet and receiving and relaying information signals to and from locations around the planet. They orbit the planet, meaning they circle the planet without falling toward the Earth or moving away from it. This happens due to the Earth's gravitational influence on the motion of the satellite. The satellite is sent into motion perpendicular to the plane of the Earth's surface. As it moves perpendicularly to the planet, gravity also pulls the satellite toward it. The net result is that the satellite moves in a constant circle around the planet. Satellites can orbit the planet and perform their functions for years on end before needing to be replaced.