The Earth is divided into seven continents: Africa, Antarctica, Asia, Australia (also called Oceania), Europe, North America, and South America. Together, they account for all of the planet's landmass. Asia is the largest by area, covering roughly 44.6 million square kilometers—about 30 percent of the Earth's total land—while Australia is the smallest at approximately 8.5 million square kilometers, though some classifications consider it the world's largest island rather than a true continent.
These continents differ greatly in their political makeup. Africa has the most countries, with 54 recognized sovereign states, and is also the second-largest and second-most-populous continent. Antarctica stands apart as the only continent with no permanent human population; it instead hosts rotating crews at research stations, typically housing between 1,000 and 5,000 people depending on the season.
The continents also vary widely in their physical extremes, ranging from icy Antarctica to tropical Africa, from the deserts of Australia to the dense forests of South America. Understanding these broad continental divisions is the first step toward grasping the world's geography, because most of the planet's physical features—rivers, mountains, deserts, and biomes—can be organized by the continent on which they appear.