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.
List of islands of Denmark
Another common criterion is that an "island" needs to be surrounded by free-flowing, natural water and not just an artificial, narrow canal. According to this criterion, places such as Christianshavn and Holmen in Copenhagen, although sometimes referred to as artificial islands, are actually parts of the island of Amager.