Now for the fun bit: Everyone from England, Scotland and Wales is also British, but not people from Northern Ireland who are Irish (despite also being UK citizens). People from the Republic of Ireland are just Irish. And, none of these groups, except for people from England, should be referred to as English. 

If that doesn’t fully make sense, then watch the video below which explains it in even more detail:   In fact, the official name of the country is the "United Kingdom of Great Britain and Northern Ireland."

The capital city of the United Kingdom is London and the head of state is currently Queen Elizabeth II. The United Kingdom is one of the founding members of the United Nations and sits on the United Nations Security Council.

The creation of the United Kingdom heralds back to 1801 when there was a unification between the Kingdom of Great Britain and the Kingdom of Ireland, creating the United Kingdom of Great Britain and Ireland. In the 1920s, southern Ireland gained independence and the name of the modern country of the United Kingdom became the United Kingdom of Great Britain and Northern Ireland.  

GREAT BRITAIN

Great Britain is the name of the island northwest of France and east of Ireland. Much of the United Kingdom consists of the island of Great Britain. On the large island of Great Britain there are three somewhat autonomous regions: England, Wales, and Scotland.

Great Britain is the ninth largest island on Earth and has an area of 80,823 square miles (209,331 square kilometers). England occupies the southeast portion of the island of Great Britain, Wales is in the southwest, and Scotland is in the north.

Scotland and Wales are not independent countries but do have some autonomy from the United Kingdom with respect to internal governance.