Why is England or the UK sometimes called Britain?
'When people say England, they sometimes mean Great Britain,
sometimes the United Kingdom,
sometimes the British Isles - but never England.'
'How to be an Alien' by George Mikes
"England" is sometimes, wrongly, used in reference to the whole United Kingdom, the entire island of Great Britain (or simply Britain), or indeed the British Isles. This is not only incorrect but can cause offence to people from other parts of the UK. (See nationality of the British people).