Great Britain is an Island. England is one country and geographical region within that island. Wales and Scotland are the other countries within that island.

Great Britain is an Island. England is one country and geographical region within that island. Wales and Scotland are the other countries within that island. Some of the surrounding islands are respectively part of the countries of England, Scotland and Wales. The UK is the state, the British state. It operates within Great Britain (and its surrounding islands), and part of the island of Ireland - i.e Northern Ireland. The meaning of Britain varies with context, sometimes it refers to the state (the UK), sometimes the island of Great Britain. The City is the square mile of London, a quasi city state which in some respects is not even part of the state (see the Norman Conquest of England), but that is usually ignored. The Commonwealth currently refers to parts of what were previously the British Empire. Officially, the UK exited, as the UK was the member. However, arrangements were made for Northern Ireland such that it sort of stayed within the Single Market (for Goods) and observes EU customs rules. Hence GB fully exited, NI exited, but has special arrangements such that many aspects of EU law still apply. The headline is trying to indicate that Brexit had detrimental effects, but only because the UK did succeed in leaving the EU. If it had not managed to leave, there would have been none of the complained of detrimental effects - i.e. the 'failure'.