A continent is a large area of the land on Earth that is joined together.

There are no strict rules for what land is considered a continent, but in general it is agreed there are six or seven continents in the world, including Africa, Antarctica, Asia, Europe, North America, Oceania(or Australasia), and South America.

Demography

The most populous continent by population is Asia, followed by Africa. The third most populous continent is Europe. The fourth most populous is North America, and then South America. In sub-Saharan Africa, the largest age group are denarians (in their teens). In north Africa, the largest age group are vicenarian (in their twenties). In Europe, most people are tricenarian (in their thirties) or quadragenarian (in their forties).

Continents 
Geologists use the term continent to mean continental crust, a platform of metamorphic and igneous rock, largely of granitic composition. Continental crust is less dense and much thicker than oceanic crust, which is why it "floats" higher than oceanic crust on the underlying mantle. This explains why the continents form high platforms surrounded by deep ocean basins.

Australia 
Some sources say that Australia is one of the seven continents. Others say that Australia is part of a larger continent, such as Australasia, or Oceania. Oceania is a region which includes Australia, New Zealand and the Pacific Islands. Australasia includes at least all countries on the Australian continental plate. This includes the islands of New Guinea, Tasmania, New Zealand and a number of smaller islands. It is on the south-eastern side of the Wallace Line, with distinct differences in its biology from the Asian side of the line.

"It includes all the islands of the Malay Archipelago... as well as the various groups of islands in the Pacific. The term has been used in very different senses".

North and South America 
North America and South America together are often described as one continent, "the Americas", or simply "America". This has the advantage of including Central America and the Caribbean islands. Otherwise, Central America is counted as part of North America.

Eurasia 
Eurasia is not really an alternative, rather it is a recognition that the landmasses of Europe and Asia are continuous, and some of its largest countries are in both regions. Russia extends from eastern Europe to the far east of Asia without a break. The Ural Mountains, which run roughly north–south, are the traditional dividing-line between Europe and Asia. For many purposes it is convenient to consider the great landmass as a single continent, Eurasia.

When British people talk about "the Continent" (or "Continental" things) they mean the European mainland. This meaning is not used as much as it used to be, but is still seen in phrases like "Continental breakfast" (rolls with cheese, jam etc. as distinct from an "English breakfast" which is a cooked breakfast).

Continents not only move but also sometimes move against each other. The Indian subcontinent has been colliding with the Eurasian continent for a while now. As these continents push against each other, they buckle and bend. Because of this, the Himalaya Mountains, where Mount Everest is, are still being made today.

Antarctica 
Antarctica is Earth's fifth largest continent. Antarctica is the coldest place on Earth, covers Earth's South Pole. The continent only have two seasons, summer and winter. Antarctica is a desert, it does not rain or snow a lot there. Ever since its discovery in 1812, Antarctica with a surface area of ~13.6 –14 million km2 about 1.4 times the size of Europe, proved to be a great challenge for explorers. Despite being nearly completely covered by a thick layer of ice, Antarctica harbors a wide range of aquatic and terrestrial environement.

Zealandia 
Zealandia is an almost entirely submerged land mass, and 93% of it still remains under water. Zealandia may have broken off the Australian plate between 85 and 130 million years ago.

Related pages
 List of countries by continents

References 

 
Geology