The Pacific Ocean has an estimated 20,000 to 30,000 islands; the exact number has not been precisely determined. These islands are also sometimes collectively called Oceania (although Oceania usually also includes Australia), and are traditionally grouped into three: (1) Melanesia, (2) Micronesia, and (3) Polynesia.
Melanesia means black islands. These include New Guinea (the largest Pacific island,which is divided into the nation of Papua New Guinea and the Indonesian province of Irian Jaya), New Caledonia, Vanuatu, Fiji, and the Solomon Islands
Micronesia means small islands. These include the Marianas, Guam, Wake Island, Palau, the Marshall Islands, Kiribati, Nauru, and the Federated States of Micronesia.
Polynesia means many islands. These include New Zealand, the Hawaiian Islands, the Midway Islands, Samoa, American Samoa, Tonga, Tuvalu, the Cook Islands, French Polynesia, and Easter Island.
There are also many other islands located within the boundaries of the Pacific Ocean, but these are not considered part of Oceania. These islands include the Galapagos Islands of Ecuador; the Aleutian Islands in Alaska; the Russian islands of Sakhalin and Kuril Islands; the island nation of Japan, which includes the Ryukyu Islands; Taiwan; the Philippines; the South China Sea Islands; and most of the islands of Indonesia. However, it should be noted that the inhabitants of these islands are not considered to be Pacific Islanders and are usually identified with their nearest continent.