The authors' explores the geographic realities behind their concept of islands. They develop a terminology for islands that corresponds to scientific observations gleaned from geological, biological and human perspectives. When looking at a globe or world map, the emerged lands of the blue planet constitute a sort of 'world archipelago'. The two mainlands of the world archipelago are the Old World and the New World of North America. The distribution of islands according to latitude shows that most of them are located in the northern hemisphere, despite the fact that this has a lower proportion of ocean. There are three main 'mega-archipelagos' in the world: the group bounded by Sumatra, Timor, the Solomons and Philippines; the archipelagos of northern Canada; and the Caribbean. Air travel, radio, telephone, satellite connections, the internet and other new technologies of transportation and communications have reduced island isolation in some cases and increased it in others.