In English-speaking countries continents are thought of as large landmasses (and that might be the technical geological definition too) so that is why they call it Australia more often than Oceania. Oceania is Australia + New Zealand + Polynesia/Micronesia/Melanesia, which is more of a region I guess.
People live under the ice, what the... That's so bloody cool! I didn't think that was possible. Lemme Google some images
Stop acting dumb... there are a few dozen people who live on Antarctica permantly and a few thousand temporarily, look it up... People have been born there
