>Which entities make up the "United Kingdom?"

England, Scotland, Wales and Northern Ireland form the United Kingdom.

Jersey, Guernsey and the Isle of Man are Crown Dependencies and are not
part of the UK. They have the same head of state (i.e. the British
monarch), but they have their own separate governments. They also have
certain relationships with the EU, but are not part of it.

The Overseas Territories have vary relationships with the UK, but none are
part of it. Some are self-governing (e.g. Bermuda, Anguilla) and are pretty
much countries in their own right, whilst others are administered directly
(e.g. the Cyprus SBAs and the BIOT). With the exception of Gibraltar, none
are part of the EU.

Whilst the UK in practice assumes certain responsibilities (e.g. defence
and foreign relations) on behalf Crown Dependencies and Overseas
Territories, this is invariably done in the name of the monarch (through
the Privy Council).

>And how about the "Commonwealth"?

The Commonwealth is a political organisation of 53 countries, but this
includes 16 Commonwealth Realms. These are sovereign countries that share a
monarch with the UK (e.g. Australia and Canada), although the monarch is
head of state in her own right in those countries (e.g. Queen of Australia).

Again, apologies for the lack of multidimensional content, but the question
was asked.

Regards,

Kevin Meynell