What are the operational and technical differences between Category II and III ILS approaches?
Operationally, CAT II you see the runway, CAT III you don't. Technically, one can be landed manually, the other requires an autoland. Unless approved CAT III with HUD.
Explain the difference between, lnav, vnav, and lpv approaches.
LNAV think VOR approach, lateral guidance. VNAV think the acft is flying an "ILS glide path" based on the Top of Descent and End of Descent point. Assuming inputted correctly. You can have VNAV engaged during LOC app. You can (should) have LNAV and VNAV engaed during a non-precision app. LPV - Localizer Performance with Vertical guidance. Need on Ops Specs, basically GPS approach. Not that I've ever flown one.
OMG, nevermind....I thought you guys were asking. Now I realize those were essay topics.