What is 'GPS Tracking'?
A GPS receiver is a passive device which, by receiving and interpreting the signals emitted by the GPS satellites, knows how to calculate its position in the earth's surface (latitude, longitude, height, speed, etc).
The receivers by themselves are not very useful, but they become very powerful tools when integrated in other devices. For example, the popular GPS navigators integrate GPS receivers with a mapping application that can show the receivers location on a map, enabling useful scenarios like calculating a route from the receivers location to another arbitrary location in the map, giving us a route to follow.
Giving that the GPS receivers are passive devices, there is no way to know the location of one of them without the help of an additional communication mechanism. By coupling a GPS receiver with that additional mechanism we come up with a GPS Tracker.
That way, a GPS Tracker is composed of a GPS receiver and a communications system, normally a basic mobile phone, that allows the tracker to communicate with the outside world. We can ask for its location on demand or have the tracker report its location on a periodic basis to some known server.
One of the most common use cases is to send an SMS message to the tracker (remember we have a mobile phone there) with a text content that the tracker understands and that, once interpreted, will respond to, normally with another SMS that contains its current location information.
Uno de los usos más comunes es el de enviar un mensaje SMS al localizador (recordemos que en esencia es un teléfono móvil) con un texto concreto que el localizador entiende y que, una vez interpretado, responderá, normalmente con otro mensaje SMS, con los datos que correspondan en ese momento.
In the case of TrackStep, the application is capable of 'talking to' a variety of GPS Trackers from different brands by sending them specially crafted SMS messages and interpreting the responses they send back. That way you have in the palm of your hand, on your mobile phone, the locations of the trackers you own.