GPS expands to mean Global Positioning System and in layman words, it is defined as a versatile set-up or network of multiple satellites orbiting around the earth which is capable of emitting signals that can detect the position of the signal receiver's anywhere on this earth. The GPS mechanism revolves around just two factors, the distance of the satellites amongst themselves and the signal receiver. Generally, there are three to four signal satellites, four to be precise that keeps transmitting signals regularly on a real-time basis. While they are transmitting signals it gauges the position of the satellite and the precise time of transmission, which means where ever you are on the earth, the four GPS satellites are active, while they are transmitting information about each other's position and in meanwhile, when you put on the GPS then you become the intermediate GPS signal receiver. When the signals transmitted by the satellites is intercepted by the GPS receiver, it calculates how far the satellites are from its current position and the time taken to receive this information. Once this information is received the GPS system can tell the user its current location and this entire process is generally called trilateration.
GPS these days is a concept that is widely used in all types of industrial sector like mining, agriculture, production, military, and aviation. It can also be used for personal ease and use of a normal user, not only is it used in different industrial sector but it is also used in different ways such as location detector, to determine the position of the GPS user; navigation, to get the location and route of going from one place to another; tracking, to monitor the movement of something; mapping; and timing, gauging the different timings around the world under one roof.
As you know the crux of the GPS mechanism lies in finding out the position of the GPS signal receiver, so the GPS tracker works on the same mechanism. A GPS tracker aims at a location where something actually is tracking the location of the GPS receiving a device, which can be placed anywhere Vis-à-vis a vehicle which can be a car, or a truck, or motorcycle etc, mobile phones, and special GPS-abled devices.
The GPS-abled devices are now available to normal users in different forms in various market platforms. These variants include real-time mini spy GPS tracker especially meant for car trucks, trip recorder, all-in-one GPS tracker for car, motorcycle, truck, vehicle etc. The all-in-one GPS tracker requires no installation and no wiring. Other variants include a personal GPS tracker equipped with internal memory slot, real-time precise GPS tracker- a car tracking device, an OBD plug equipped auto tracking system- a vehicle GPS tracker especially meant for cars, real-time GPS tracker that gives trip history and geofence alert and also has wi-fi hotspot, portable global GSM/GPRS/GPS tracker which can be installed in vehicles, bikes, cars, kids, pet GPS tracking, and there are many more. Some are also equipped with anti-theft tracking alarm to ensure utmost security.