Just to confuse ...
Isle of Man, Channel Islands (Jersey, Guernsey etc.) are Crown Dependencies
Gibralter, Falkland Islands, Ascension Island and St. Helena etc. are British Overseas Territories
Scilly Isles, Isle of Wight, Lundy Island etc. are part of England and thus part of the UK
Isle of Anglesey is part of Wales and thus part of the UK
Isle of Skye is part of the Inner Hebrides which are a chain of islands which are a part of Scotland and thus part of the UK
Rathlin Island is part of Northern Ireland and thus part of the UK
That's enough Islands ...