Britain (or Great Britain) and the United Kingdom (or the UK) include England, Scotland, Wales and Northern Ireland. (Sometimes Britain or Great Britain is used just for the island which includes England,
Scotland and Wales, without Northern Ireland.)
The British Isles is the name for England, Scotland, Wales, the whole of Ireland, and all the islands round about.
Note that England is only one part of Britain. Scotland and Wales are not in England, and Scottish and Welsh people do not like to be called 'English'.
6R£AT PRfTAIN OR. THE UNITED KINGDOM
THE gRlTtSH ISLES