The United Kingdom (UK) does not share land borders with any countries, as it is an island nation. However, it is located close to the mainland of Europe, specifically bordered by the Republic of Ireland to the west.
The UK is made up of four countries: England, Scotland, Wales, and Northern Ireland. While England, Scotland, and Wales are part of Great Britain, Northern Ireland is located on the island of Ireland, which is shared with the Republic of Ireland. So, to clarify, the only direct border the UK has is with the Republic of Ireland.
This unique geographical situation means that while the UK is surrounded by bodies of water like the English Channel to the south and the North Sea to the east, its only land connection with another country is with the Republic of Ireland. Travel between the UK and other countries typically occurs via air or sea.