The United Kingdom is a political union comprising of England, Northern Ireland, Scotland and Wales (sometimes referred to as the four "constituent countries" of the United Kingdom) and includes the island of Great Britain, the northeast part of the island of Ireland and many small islands. The capital city is London. The population of United Kingdom is approximately 60.5 million people and the official language is English. Scotland is a country that is part of the United kingdom. It covers an area of 30,414 square miles and has a population of approximately 5.2 million people. The capital city is Edinburgh and the official language is English.