Oceania is a geographical region including Australasia, Melanesia, Micronesia, and Polynesia. Outside of the English-speaking world, Oceania is generally considered a continent, while Australia is regarded as an island or a continental landmass within that continent. Spanning the Eastern and Western Hemispheres, at the centre of the water hemisphere, Oceania is estimated to have a land area of about 9,000,000 square kilometres (3,500,000 sq mi) and a population of around 44.4 million as of 2022. Oceania is the smallest continent in land area and the second-least populated after Antarctica.