Continent

A continent is one of several very large landmasses on Earth. They are generally identified by convention rather than any strict criteria, with up to seven regions commonly regarded as continents. These are (from largest in size to smallest): Asia, Africa, North America, South America, Antarctica, Europe, and Australia. In geology, areas of continental crust include regions covered with water.

Definitions and application

By convention, "continents are understood to be large, continuous, discrete masses of land, ideally separated by expanses of water." Many of the seven most commonly recognized continents identified by convention are not discrete landmasses separated completely by water. The criterion "large" leads to arbitrary classification: Greenland, with a surface area of 2,166,086 square kilometres (836,330 sq mi) is considered the world's largest island, while Australia, at 7,617,930 square kilometres (2,941,300 sq mi) is deemed the smallest continent.

The Earth's major landmasses all have coasts on a single, continuous world ocean, which is divided into a number of principal oceanic components by the continents and various geographic criteria. The definitions of continents are sometimes extended beyond the major landmasses, in a way that every bit of land on earth is included in a continent.