Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. Comprising six states and ten territories, Australia has a total area of 7,688,28…Australia, officially the Commonwealth of Australia, is a country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. Comprising six states and ten territories, Australia has a total area of 7,688,287 km², making it the sixth-largest country in the world and the largest country by area in Oceania. It is the world's oldest, flattest, and driest inhabited continent, with some of the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates including deserts and tropical rainforests.