The GPS or the Global Positioning System is a brainchild of the U.S. Department of Defense. It was extended for the use of the civilians only during the 1980s. The technology employs 24 to 32 medium Earth orbit satellites to map the real-time location of the receiver embedded in the device. The receiver is made to lock the signal from three or more satellites to mark the location, using a technique called trilateration. The time taken for the signals sent from the satellites to reach the receiver is used in the calculation of the position. From distance to the destination, hiking and water maps, sunrise and sunset timings and much more, GPS has a galore of real-time information.