Africa is the world's second-largest and second-most-populous continent, after Asia. At about 30.2 million km² (11.7 million sq mi) including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area. With 1.0 billion people (as of 2009), it accounts for about 14.72% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast, and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It has 54 fully recognized sovereign states (countries), 9 territories and three de facto states with limited recognition.
The Caribbean is a crescent-shaped group of islands more than 2,000 miles (3,200 km) long separating the Gulf of Mexico and the Caribbean Sea, to the west and south, from the Atlantic Ocean, to the east and north. From the peninsula of Florida on the mainland of the United States, the islands stretch 1,200 miles (1,900 km) southeastward, then 500 miles (800 km) south, then west along the north coast of Venezuela on the South American mainland. Situated largely on the Caribbean Plate, the region comprises more than 7,000 islands, islets, reefs, and cays. These islands generally form island arcs that delineate the eastern and northern edges of the Caribbean Sea.
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent. Central America consists of the seven states of Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama. Central America is part of the Mesoamerican biodiversity hotspot, which extends from northern Guatemala through central Panama. It is bordered by Mexico to the north, the Caribbean Sea to the east, the North Pacific Ocean to the west, and Colombia to the southeast.
Europe is the world's second-smallest continent by surface area, covering about 10,180,000 square kilometres (3,930,000 sq mi) or 2% of the Earth's surface and about 6.8% of its land area. Comprising the westernmost peninsula of Eurasia, Europe is generally divided from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting the Black and Aegean Seas. Europe is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and the Black Sea and connected waterways to the southeast. Yet the borders of Europe—a concept dating back to classical antiquity—are somewhat arbitrary, as the primarily physiographic term "continent" can incorporate cultural and political elements.
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the west and south by the Pacific Ocean, and to the southeast by South America and the Caribbean Sea. North America covers an area of about 24,709,000 square kilometers (9,540,000 square miles), about 4.8% of the planet's surface or about 16.5% of its land area. As of July 2008, its population was estimated at nearly 529 million people across 23 independent states. North America is the third-largest continent in area, following Asia and Africa, and the fourth in population after Asia, Africa, and Europe.
Oceania is a region centered on the islands of the tropical Pacific Ocean. Opinions of what constitutes Oceania range from the coral atolls and volcanic islands of the South Pacific ethnologically divided into the subregions of Melanesia, Micronesia, and Polynesia to the entire insular region between Asia and the Americas, including Australasia and the Malay Archipelago. The term is sometimes used more specifically to denote a continent comprising Australia and proximate islands, or biogeographically as a synonym for either the Australasian ecozone (Wallacea and Australasia) or the Pacific ecozone (Melanesia, Polynesia, and Micronesia apart either from New Zealand or from mainland New Guinea).
South America is a continent located in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. It includes twelve independent countries—Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela—as well as French Guiana, which is an overseas region of France and the Falkland Islands of the UK. In addition to this, the ABC islands of the Netherlands may also be considered part of South America. The South American countries that border the Caribbean Sea—Colombia, Venezuela, Guyana, Suriname, and French Guiana—are also known as Caribbean South America.