Global Positioning System (GPS)
Wikipedia : space-based satellite navigation system that provides location and time information in all weather conditions, anywhere on or near the earth where there is an unobstructed line of sight to four or more GPS satellites.
With today mobile technology neatly in the palm of your hand, apps such as maps google and waze has become essential for knowing where your are and how you going to to some where else from one point. All thanks to technological system called Global Positioning System or GPS.