GPS means Global positioning System
GPS is developed by the U.S. Army. It is a system of satellites in permanent orbits around the Earth. Every spot on Earth always sees at least 3 satellites, which are also needed to be able to do a positioning. This is done by means of radio waves and the fact that the position of the satellites is known. Navigation software like TomTom and Garmin use GPS to determine the current location of someone. Many hikers and cyclists also use it to track their travelled route, or to follow a pre-set route. Order your GPS system: www.GPSshop.nl https://www.youtube.com/watch?v=IoRQiNFzT0k