High Quality Content by WIKIPEDIA articles! Oceania is a region centered on the islands of the tropical Pacific Ocean. Conceptions of what constitutes Oceania vary, with it being defined in various ways, often geopolitically or geographically. In the geopolitical conception used by the United Nations, International Olympic Committee, and many atlases, the Oceanic region includes Australia and the nations of the Pacific from Papua New Guinea east, but not the Malay Archipelago or Indonesian New Guinea.. The term is sometimes used more specifically to denote Australasia as a geographic continent, or biogeographically as a synonym for either the Australasian ecozone (Wallacea and Australasia) or the Pacific ecozone (Melanesia, Polynesia, and Micronesia apart either from New Zealand or from mainland New Guinea).