Satellites serve a number of functions, from weather prediction to communications and providing television programming. Satellites also provide GPS, or global positioning, data that powers GPS devices to show an exact location on the planet.
Thousands of satellites orbiting the Earth take pictures of the planet that are useful in predicting weather or tracking weather systems. Other satellites are used to map the universe and take pictures of heavenly bodies to gain understanding of space. Perhaps the most common use of satellites is transmitting television programming into homes and businesses. One large group of satellites form the Global Positioning System, or GPS, that is useful in GPS navigation systems, phones and military applications.