I have been active on APRS, the Automatic Packet Reporting System since 2008.
Rather than bore you with the details, take a look at wikipedia which explains all. If you are in the UK, M0CYP has a great site with lots of information on settings and how to use UI-VIEW, the most popular APRS software.
I have two stations. One at GB2GP that runs as an I-gate and another remote tracker in my car.
If you are active on APRS in the UK, please note that IARU region 1 has adopted the "new paradigm" settings. The new recommended system for the UK is explained by M0CYP which also covers the changes that should be made to UI-VIEW.
The aprs.fi does a great job of real time mapping, so take a look for the car or my house using the embedded website image below.