Let me see if I can help a bit here....
The different symbols dictate the signal being sent. The images denote, in a nutshell, what vehicle a person may be driving in.... ie a car, bus, truck, fire department vehicle, police car etc. The operator chooses which "vehicle" they wish to show they are driving, thus why you might see a sailboat driving down the I-55 for example. As a general rule, though most operators are responsible enough to change their icons to whatever they are commuting in.
A fixed station might be a digitial repeater (digipeat) or simply a repeater. This means it is receiving the information and rebroadcasting it out again so the signal can be tracked across the USA by being relayed or repeated out various places.
Home stations can rebroadcast both as a repeater, over the air, or repeat via the Internet so one can track via the Internet, commonly known as Igates. Amateur Repeaters usually only rebroadcast via radio waves, or repeaters though this is ever changing.
A station with a WX symbol is basically a permanent station sending out weather data for that area.
A station with a house means it is being sent from a house, and generally is a relay of all signals being received.
You may see a callsign followed by a -1, -2, -3 etc. All this means is the amateur radio station has multiple broadcasting stations.
Example... K3JAE-1 would be my permanent home station.
K3JAE-2 would be my Weather station only broadcasting info (permanent as well).
K3JAE-3 would be my vehicle as I move about, most likely broadcasting from a Mobile unit.
K3JAE-4 could be assigned as my portable radio if I am on foot working an event etc.
All stations assign their designators differently but this is generally the most common way to so it.
APRS is designed to be a GPS tracking utility.
Hope this helps.
73's de K3JAE
