Here's a quick rough-cut video going over APRS. I'll start with some of the high-level technical bits of "WHAT" APRS is, and then I'll dive into the more practical "WHY" you might want to use it.

I start off with the technical stuff, so if you want to skip that and go right to the practical stuff, use these timestamps to jump around:

INTRO: 01:18
Technical Overview: 01:51
Practical APRS: 05:26