Now that the stateside parallel is established, it’s time head across the pond to address the usages of Great Britain vs. the United Kingdom. The difference between the two, at least in the modern day, is also based in political and geographic naming.
Great Britain is another name for the island of Britain, which, politically, is composed of Wales, Scotland, and England. When used in a political sense, it extends the island’s boundaries a bit to include some outlying islands, such as Anglesey and the Isle of Wight.
The United Kingdom, however, does not cut both ways, as it is a purely political term. The U.K. is an independent country composed of Scotland, Wales, Northern Ireland, and England. All of Great Britain is within the United Kingdom, but the United Kingdom is not 100 percent composed of Great Britain. Make sense?
Next, make sure you stop making these 30 geographical mistakes everyone gets wrong.
[Source: Encyclopedia Britannica]