Islands are areas of land that are not connected to a continent and are surrounded by water. Small islands are sometimes called cays, keys, or islets. A group of islands is often called an archipelago.

There are two main type of islands; continental islands and oceanic islands. Continental islands are part of a continental shelf. One example of this is Great Britain is an island that sits on the continental shelf of Europe. Oceanic islands are islands that don't sit on a continental shelf. Many oceanic islands are formed by undersea volcanoes like Hawaii in the Pacific Ocean.

Below are some of the major islands in the world:

Greenland

Greenland is by far the world's largest island that is not a continent. It covers 822,706 square miles which is more than double the second largest island, New Guinea. For such a large island, Greenland only has a population of around 56,000 people making it one of the least densely populated places in the world. This is because most of Greenland is covered by a sheet of ice. Greenland is part of the continent of North America, but politically has generally been part of Europe through the country of Denmark.

Great Britain

Great Britain is the ninth largest island in the world and is the largest island in the British Isles. It is the third most populated island in the world. The British Empire was centered here and at its peak in the 18th to 20th century was the largest empire in the history of the world. It is part of Europe and is located off the northwest coast of France.

Madagascar

Madagascar is the fourth largest island in the world. It's located off the southeast coast of Africa. Madagascar is home to many animal and plant species that can't be found anywhere else on the planet. Around 80% of the plant and animal life on the island can only be found on Madagascar. It is so unique some scientists refer to it as the eighth continent.

Originally posted here:

Geography for Kids: Islands - Ducksters