Terminology of the British Isles
Various words and phrases have been used to describe the occasionally overlapping geographical and political areas of the islands of Great Britain, Ireland, and the smaller surrounding islands, together known as the British Isles. The terms are often a source of confusion, partly owing to the similarity between some of the actual words used but also because they are often used loosely.
Source: Wikipedia — Terminology of the British Isles (CC BY-SA 4.0)