The British Isles

As you all know by now or will do after reading this, the British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland, and over six thousand smaller islands.

Anyway, as usual, English speaking people do not agree on which term to use so you will also find, apart from the aforementioned, the following ones British-Irish Isles, Britain and Ireland, Great Britain and Ireland, British Isles and Ireland or UK and Ireland; in any case all those terms refer to the same territory.
Etimológicamente parece ser que las primeras referencias a las islas como grupo las hicieron unos viajeros griegos que las llamaron en latín Prettania y que más tarde, en tiempos de Julio César pasaron a ser Brittania.