The United Kingdom of Great Britain and Northern Irel commonly known as the United Kingdom or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises Engl Scotl Wales and Northern Ireland. The United Kingdom includes the island of Great Britain, the north-eastern part of the island of Irel and many smaller islands within the British Isles. Northern Ireland shares a land border with the Republic of Ireland; otherwise, the United Kingdom is surrounded by the Atlantic Ocean, the North Sea, the English Channel, the Celtic Sea and the Irish Sea. The total area of the United Kingdom is 242,495 square kilometres , with an estimated 2023 population of over 68 million people.