The official name (title) of this state is The United Kingdom of Great Britain and Northern Ireland. We can use shorter names such as the United Kingdom or the British Kingdom.A lot of people use only the name „ Great Britain “ , but it isn´t right. It´s the same , as if you wanted to talk about the USA and you would say such name of its part, f.e. California. Great Britain is only a part of UK. ( Exactly) the UK consits only of islands and Great Britain is the largest one.Ireland is the second largest one.
Now I´d like to say something about 2 parts of these islands.About northern part of GB called Scotland and about northern part of Ireland called Northern Ireland.