GPRS or General Packet Radio Service is a network that extends GSM with new capabilities. GPRS allows mobile devices to send/receive IP data such as accessing email, browsing web, instant messaging. GPRS is available with every GSM cellular network. So where one works, the other is pretty sure to work too.
Vehicle tracking systems mostly use GPS. However, in some cases GPRS can be used to effectively track anyone. GPRS can also track in real time like GPS. Instead of satellites, GPRS determines the target location using nearby GSM cellular station networks. GPRS is more flexible that GPS due to its nature and allows more advanced data to be transferred through the network.