Oceania are the islands throughout the Pacific Ocean.
The three regions that comprise Oceania are: Micronesia, Melanesia and Polynesia. All these are island regions.
Micronesia is a group of small islands in the western Pacific Ocean.
Melanesia is the group of islands from New Guinea island in the southwestern Pacific Ocean to the Arafura Sea.
Polynesia is a group of islands scattered over the central and southern Pacific Ocean.
