Global Positioning System or GPS
GPS - Global Positioning System What is GPS ? GPS Definition : Global Positioning System The Global Positioning System, usually called GPS, and originally named NAVSTAR, is a satellite-based navigation system used for determining ones precise location and providing a highly accurate time reference almost anywhere on Earth. A GPS unit uses these "man-made stars" as reference points to calculate positions accurate to a matter of meters. The GPS was designed by and is controlled by the United States Department of Defense and can be used by anybody for free.