The primary use of the term Oceania is to describe a continental region (like Europe or Africa) that lies between Asia and the Americas, with Australia as the major land mass. The name Oceania is used, rather than Australasia, because unlike the other continental groupings, it is the ocean rather than the continent that links the nations together. Oceania is the smallest continental grouping in land area and the second smallest, after Antarctica, in population.
By far the largest part of Australia is desert or semi-arid. Australia is the driest inhabited continent, the flattest, and has the oldest and least fertile soils. Only the south-east and south-west corners of the continent have a temperate climate. The majority of the population of 20.4 million (Sep 2005 est) lives in these temperate zones. The capital is Canberra.
The atoll consists of an extensive reef, two shallow lagoons, and some 50 sand and reef-rock islets and bars covered with vegetation—mostly coconut trees, Scaevola, and tall Pisonia trees. The islets of the atoll are all connected, except Sand Island and the two Home Islets in the west and Barren Island in the east. Average annual rainfall is approximately 175 in (4,400 mm) per year. Daytime temperatures average 85 °F (29 °C) year round.