Ireland is an island in the North Atlantic separated from Great Britain to its east by the North Channel, the Irish Sea, and St George's Channel. It is the second-largest island of the British Isles after Great Britain, the third-largest in Europe and the twentieth-largest on Earth.
Politically, Ireland is divided between the Republic of Ireland (officially named Ireland), which covers five-sixths of the island, and Northern Ireland, a part of the United Kingdom, which covers the remaining area and is located in the north-east of the island. In 2011 the population of Ireland was about 6.4 million, ranking it the second-most populous island in Europe. Just under 4.6 million live in the Republic of Ireland and just over 1.8 million live in Northern Ireland.