Ben Drawbaugh posted a nice primer on High Definition Acronyms over at EndgadgetHD.
What is ATSC, PSIP, QAM and 8-VSB?
Prepared to geek out a little with Ben (he's insanely good at this HD technical stuff) and learn a bunch about the basic terminology of HD Technology. I consider this a highly recommended read if you're interested in High Definition at all. At least skim it and read up on the terminology you might not know or understand.