continents

The continents are the world's seven great land masses which are continuously coming together and drifting apart. The earth's outer shell (crust) is made up of nine major moving slabs of rock, called tectonic plates, in which the continents are embedded. Over millions of years, the continents' placement has changed dramatically. Two hundred and twenty million years ago, all the continents were joined into a single 'supercontinent' we refer to as Pangaea. The word continent comes from Latin continens, short for terra continens, meaning "land held together."