Great Britain is the official name given to the two kingdoms of England and Scotland, and the principality of Wales. The United Kingdom (UK) includes these areas as well as Northern Ireland. Britain refers to only England and Wales, though some will shorten Great Britain with this term.
The UK, officially known as the United Kingdom of Great Britain and Northern Ireland, makes for an interesting country. Like every other nation, UK too has idiosyncratic patterns in behaviour, language, and culture. Make sure that you strictly adhere to every guideline that has been compiled for a great, blunder-free visit to this stupendous island nation:
GREAT BRITAIN: England, Wales and Scotland. It is ONE island (the eastern one). UNITED KINGDOM: England, Wales, Scotland AND Northern Ireland. IRELAND: a separate country British Isles: all countries in both countries.