Oceania also known as Oceanica, is a region centred on the islands of the tropical
Pacific Ocean. Opinions of what constitutes Oceania range from its three subregions
of Melanesia, Micronesia, and Polynesia to, more broadly, the entire insular region
between Southeast Asia and the Americas, including Australasia and the Malay
The term is often used more specifically to denote a continent comprising Australia
and proximate islands or biogeographically as a synonym for either the Australasian
ecozone (Wallacea and Australasia) or the Pacific ecozone (Melanesia, Polynesia,
and Micronesia, excluding both New Zealand and mainland New Guinea).