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.
Terminology of the British Isles
Under the Interpretation Act 1978 of the United Kingdom, the legal term British Islands (as opposed to the geographical term "British Isles") refers to the United Kingdom of Great Britain and Northern Ireland, together with the Crown dependencies: the Bailiwicks of Jersey and of Guernsey (which in turn includes the smaller islands of Alderney, Herm and Sark) in the Channel Islands; and the Isle of Man.