The first thing about GPS that everyone should know is what it stands for. GPS stands for Global Positioning System is a worldwide radio navigation system formed from a constellation of 24 satellites and its ground stations.
GPS uses these satellites as reference points to calculate positions accurate to a matter of meters. GPS receivers have been miniaturized to just a few integrated circuits and they are also becoming very economical. Now a days GPS's are found in cars, boats, planes, construction equipment, movie making gear, farm machinery, and laptop computers. Eventually GPS is going to be everywhere even in basic telephones.
GPS works in five steps: