@Olivier5,
The term Europe, in most conventional use, refers to the territory between the British Isles in the west and the Ural mountains in the east, and from the Arctic to the Mediterranean. Certainly cultures languages and political systems have arisen there with numerous (though not always universal) common features to make it a meaningful thing both in history and in the organization of political, economic and cultural activity today. There have always been important dvisions within Europe, based on language, various nationalistic and ethnic concepts, religion and political systems, but they have not erased the recogniozed unifying factors that remain, either among the population or the historians who chronicle their lives.
Certainly the physical separation of Great Britain from the continental land mass has been a signifficant factor in the history of Britain, just as have been the Alps in the History of the Swiss. However both are part of Europe, and both were equally affected by the migration of peoples across the continent several millenia ago,
Geological time scales are about a million times those relating to human history, so it is no surprise that the geographical terminology of the two are inconsistent. ( not to mention the pedantical fussiness of many geologists, who appear to think their terminology should be as lasting as the rocks they love so well.)