Continent

Continent is a term from Geography, that refers to the largest land masses.

Currently, Asia, Africa, North America, South America, Europe, Antarctica and Australia are classed as continents. The next largest land masses, Greenland and Java, are not classed as continents.

In the 20th Century geologists realized that Planet Earth's surface consisted of dozens of slowly moving tectonic plates. While those plates move at mere centimetres per year, over geologic time scales, their movements cause continents to break apart, and for new continents to form, when plates collide.

There is a mid-Atlantic Ridge, roughly equidistant from the Americas, and Europe and Africa. The coastlines of these continental masses once fit together, where they broke apart as underlying plates moved apart, over the course of hundreds of millions of years.

Geologists believe there were several periods in Earth's history when all Planet Earth's land masses were contiguous, forming one single massive supercontinent.