What is APRS?

[Anonymous]

Hello OMs,


that may sound like a very stupid question, but since APRS is one 
of the topics most participiants of this list seem to be interested in 
and I have no information about it at the moment I think I must ask 
it to satisfy my curiosity:

What exactly is APRS and why are almost all of you so interested 
in that topic?
Any hints, pointers to WWW sites etc. welcome.

Thank you very much in advance and sorry for being slightly 
offtopic...just curious :)

73s de Gerd