Northern Ireland is a country located on the island of Ireland, which is divided into two separate countries: the Republic of Ireland (EIRE) and Northern Ireland (ULSTER). Northern Ireland is part of the United Kingdom and is located in the northern part of the island. It is bordered by the Republic of Ireland to the south and west, and by the North Channel and Irish Sea to the east and north respectively. Northern Ireland has a population of approximately 1.8 million people and its capital city is Belfast.