Hi,
What is the simple difference between British, Briton, and English when referring to people?
'British' is an adjective for someone who lives in Britain, consisting of England, Scotland and Wales. Some people would also argue that Northern Ireland is included, although I think that technically it isn't.
'Briton' is a noun for a British person. It is often abbreviated nowadays to 'Brit', a term which I find rather offensive but by which people who live in Britain have told me they are not offended.
'English' is an adjective for someone who lives in England.
Best wishes, Clive