Island
An island or isle is any piece of sub-continental land that is surrounded by water. Very small islands such as emergent land features on atolls can be called islets, skerries, cays or keys. An island in a river or a lake island may be called an eyot or ait, and a small island off the coast may be called a holm. A grouping of geographically or geologically related islands is called an archipelago, such as the Philippines.
Archipelago Sea
The archipelago has a very large number of islands. The exact number depends on the definition of the term "island", as the size of the patches of dry land in the area varies from small rocks peeking out of the water to large islands with several villages or even small towns. The number of the larger islands of over 1 km within the Archipelago Sea (in provinces of Åland Isles and Southwest Finland) is 257, whilst the number of smaller isles of over 0.5 ha is about 17,700. If the number of smallest uninhabitable rocks and skerries is accounted, 50,000 is probably a good estimate. In comparison, the number of islands in Canadian Arctic Archipelago is 36,563. Indonesia has 17,508 islands, according to the Indonesian Naval Hydro-Oceanographic Office. The Philippines have 7,107 islands.