I've heard all about HE-AAC, but I haven't read or heard anything at all about LC-AAC. Nero offers both choices for encoding, but I can't find anything in the Nero help files about LC-AAC. I did read somewhere, however, that low-complexity refers to audio encoding, and high-complexity refers to video+audio. So what does high-efficiency refer to? Suffice to say I'm confused.

Thanks,
spaceman

look here, it's been answered a few times already.
short: HE - for low bitrates. LC - for medium and high bitrates.

further, see here for further details.

About current bitrates corresponding to tools/profiles
http://www.hydrogenaudio.org/forums/index....ndpost&p=219314

HE AAC = LC AAC + SBR

SBR is a tool that reconstructs high frequencies.