The United Kingdom of Great Britain and Northern Ireland (commonly known as the United Kingdom, the UK, or Britain) is a sovereign state located off the north-western coast of continental Europe. The country includes the island of Great Britain, 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 sovereign state—the Republic of Ireland. Apart from this land border the UK is surrounded by the Atlantic Ocean, the North Sea, the English Channel and the Irish Sea.
The United Kingdom is a unitary state governed under a constitutional monarchy and a parliamentary system, with its seat of government in the capital city of London. It is a country in its own right and consists of four countries: England, Northern Ireland, Scotland and Wales.
The UK is a developed country and has the world's seventh-largest economy by nominal GDP and eighth-largest economy by purchasing power parity. It was the world's first industrialised country and the world's foremost power during the 19th and early 20th centuries. The UK remains a great power with leading economic, cultural, military, scientific and political influence. It is a recognised nuclear weapons state and its military expenditure ranks fourth in the world.
The flag of the UK is called the Union Jack.
The total area of the United Kingdom is approximately 243,610 square kilometres (94,060 sq mi). It lies between the North Atlantic Ocean and the North Sea with the south-east coast coming within 35 kilometres (22 mi) of the coast of northern France, from which it is separated by the English Channel.
England accounts for just over half of the total area of the UK, covering 130,395 square kilometres (50,350 sq mi).
Scotland accounts for just under a third of the total area of the UK, covering 78,772 square kilometres (30,410 sq mi)104 and including nearly eight hundred islands,105predominantly west and north of the mainland; notably the Hebrides, Orkney Islands and Shetland Islands.
Wales accounts for less than a tenth of the total area of the UK, covering 20,779 square kilometres (8,020 sq mi).
Northern Ireland accounts for just 14,160 square kilometres (5,470 sq mi) and is mostly hilly.
The United Kingdom has a temperate climate, with plentiful rainfall all year round.The temperature varies with the seasons seldom dropping below −11 °C (12 °F) or rising above 35 °C (95 °F).Heavy snowfall can occur in winter and early spring on high ground, and occasionally settles to great depth away from the hills.
The population is estimated to be around 63 million.