Great Britain - or in German "Grossbritannien" - is the big island that consists of Scotland, Wales and England.
The United Kingdom - das Vereinige Königreich - is Great Britain PLUS Northern Ireland.
Thirdly, the British Isles refers to Great Britain, Northern Ireland, the Republic of Ireland and all the little islands around those two, including places such as the Northern Isles (e.g. Orkneuy and Shetland), the Inner and Outer Hebrides, the Isle of Man and more than 6,000 (!!!) smaller isles.
But why the sceptic tone in the headline of this piece of writing? Because 'united' is what the so-called United Kingdom isn't.
Take, for example, the fees charged for studying at university level. I was checking out the prices charged by the Open University the other day.
If you want to get a Bachelor degree with the Open University and happen to live in England, you will pay, in total, £23,352 for 360 credits spread over 3 to 6 years. Quite a hefty sum, right? Almost as bad as on the Isle of Man or any other foreign country around the world: £24,552.
However, should you happen to live in Scotland, which has a devolved government that thinks that education is important and should be open to all, not just those who can afford it or who don't mind getting into debt, then it costs £7,632. For the entire degree. Just under a third of the price of an undergraduate degree (B.A. or B.Sc.) in England.
It's a similar situation in Wales. Although a tad more: £7,872. And in Northern Ireland, the price is at bargain basement level: £7,440.
So... when it comes to "united", that's one word you cannot use to describe the UK.