The Global Positioning System (GPS) is a U.S. space-based radio navigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis freely available to all. For anyone with a GPS receiver, the system will provide location and time. GPS provides accurate location and time information for an unlimited number of people in all weather, day and night, anywhere in the world.

Nowadays, GPS is helpful. We can use it when we are lost or we need go somewhere with unknown route. The GPS is made up of three parts, satellites orbiting the Earth, control and monitoring stations on Earth and the GPS receivers owned by users. GPS satellites broadcast signals from space that are picked up and identified by GPS receivers. Each GPS receiver then provides three-dimensional location latitude, longitude and altitude plus the time.