Global Positioning Systems or GPS are satellite navigational systems made-up of 24 satellites revolving round the earth. Each satellite has a corresponding receiver on the earth. The satellites orbit the earth at a height of about 12,000 miles. It makes two complete orbits everyday. The GPS satellites continuously transmit digital radio signals that contain data on the location of the satellites and the time taken for signal transmission.GPS tracking is the term given to the process of being able to locate the exact location of a receiver on earth. Now that the production cost of GPS technology is significantly lower than when it first came into existence, many companies have found new ways to make use of this technology. In GPS tracking, the user is able to keep a track of where they have been using a portable GPS device. GPS tracking can be used in a better way when it is combined with other broadcast technologies, such as a wristwatch or radio. GPS watches, for example, can be fitted with a GPS receiver, which relays a signal to a central command center equipped with GPS software systems. The central command center can track the position of the watch and transmit that information to a third party. That third party may be anyone who needs the position of the wearer urgently. In fact, a variety of such GPS phones and wristbands are sold in the market today. This serves two purposes. Firstly, it provides the driver with an integrated GPS system, without the necessity to purchase a car navigation system, or a PDA-based GPS system. It also offers the possibility to relay that information via a radio or cell phone transmitter.GPS systems have been used primarily as vehicle locators, especially in cases when a vehicle attached with such a system is stolen. The police, once informed, can find out from the control center where the vehicle is, and proceed to track it down. Tracking is also being used in other fields such as pet tracking, coordinated tracking and consumer tracking.