Broadly speaking, Oceania describes the region centred on all islands of the tropical Pacific Ocean, which are situated south of the Equator. There are many, many islands, both large and small that make up the “continent” of Oceania. The general regions that make up Oceania are Australia and New Zealand (termed Australasia), Melanesia, Polynesia, Micronesia and Southeast Asia.
A further breakdown of these regions is as follows - Melanesia consists of Fiji, part of Indonesia, New Caledonia (France), Papua New Guinea, the Solomon Islands, and Vanuatu.
Micronesia consists of the Federated States of Micronesia, Guam (USA), Kiribati, the Marshall Islands, the Northern Marshall Islands (USA), Nauru, Palau, and Wake Island (USA).
Polynesia consists of American Samoa (USA), the Chatham Islands (UK), the Cook Islands (UK), Easter Island (Chile), French Polynesia (France), Hawaii (USA), the Loyalty Islands (France), Niue (NZ), the Pitcairn Islands (UK), Samoa, Tokelau, Tonga, Tuvalu, and Wallis and Futuna (France)
Altogether, the population of Oceania is about 36 million, with all but 11 million living in Australia or New Zealand.
Interestingly the regions of Oceania were not colonised until the late 18th and early 19th centuries, when in contrast Europe and the America’s were colonised during the 17th Century and before.
The “continent” of Oceania is made up of Sovereign States and Dependent Territories.
Generally speaking Sovereign States have a political organization with a centralized government that has supreme independent authority over a geographic area, where a Dependent Territory is a territory that does not possess full political independence or sovereignty as a sovereign state yet remains politically outside of the controlling state's integral area.
Here is a listing of all Sovereign States and Dependent Territories of Oceania
Sovereign States of Oceania are:
Dependent Territories of Oceania are: