For those of you that are interested, and have wondered in the past of what these often quoted terms mean,
here's a 'down to earth' explanation, with schematics (and no maths), that explains in real layman's terms the two
approaches to amplifier design.
The author uses simple language and terms easily understood, with good humor as well and, I am sure, it will enlighten most of us about this subject.
Enjoy it!
http://homepage.mac.com/tlinespeakers/vaughn/downloads/SE-v-PP-Part1.pdf
... and...
if that was interesting, follow it up with this! Just as well written and informative.
http://homepage.mac.com/tlinespeakers/vaughn/downloads/SE-v-PP-Part2.pdf