Continent

A continent is a large landmass. On earth, seven areas are generally regarded as continents: North America, South America, Europe, Asia, Africa, Australasia and Antarctica. The definition can include the landmass and its nearby islands (thus for example, Australasia rather than just Australia).

Continents exist for geological reasons. The crust of continents is much thicker and lighter than that of oceans, and because of these reasons continents correspond to emerged land. From the point of view of geology, and more precisely in the theory of plate tectonics, there are more continents than those of geography. In plate tectonics, for example, Arabia constitutes a separate plate, partially constituted by continental crust.