The Earth’s land is not evenly distributed. Continents are the seven large continuous landmasses—Africa, Antarctica, Asia, Europe, North America, Australia, and South America. They sit atop tectonic plates and have drifted over geologic time.

Continents contain the full range of landforms and climates, from equatorial forests to polar ice. Continental crust is thicker and less dense than oceanic crust, allowing it to ride higher. The boundaries between continents and oceans are sometimes clear and sometimes gradual, as in the submerged continental shelves.

Human history has been shaped by the arrangement of continents. Ocean barriers limited contact for millennia; modern transport and communication have reduced those barriers. Geologists continue to refine the story of how the present continents assembled from older supercontinents.

• One of Earth’s seven major landmasses
• Composed of thick continental crust
• Contains diverse climates and landforms
• Moved by plate tectonic processes