UK is short for the United Kingdom, which itself is short for the United Kingdom of Great Britain and Northern Ireland; also called Britain
The UK is a sovereign state located off the north-western coast of continental Europe. The country includes the island of Great Britain (a term sometimes also loosely applied to the whole state), the north-eastern part of the island of Ireland, and many smaller islands. Northern Ireland is the only part of the UK that shares a land border with another state: the Republic of Ireland. Apart from this land border, the UK is surrounded by the Atlantic Ocean, with the North Sea in the east, the English Channel in the south and the Irish Sea in the west.