The smallest of all continents, Oceania is a collection of thousands of islands of the South-Pacific region with a total land area of 8,536,716 square kilometers. Oceania is a term used to describe a continental region between Asia and Americas. However, which countries constitute this continent varies. While some believe the Pacific regions including the volcanic islands of the South Pacific Ocean like the Melanesia and Polynesia groups and Australia, New Zealand, and Papua New Guinea, are a part of it, others exclude New Zealand and mainland New Guinea.