What is the difference between England, Great Britain and United Kingdom?

It is somewhat confusing when one toe the line of getting an exact definition of Great Britain and United Kingdom and some individuals misuse the terms in the bit to define it, but let's run some metres of explanation.

*England*

England is a country in Europe which has London as her capital city. The country is mostly seen as an Island due to her topography. It is the nation that has the famous Queen Elizabeth as the political head. England is the largest country in Great Britain and in the British Isles. It's capital city( London) also serves as the capital of Great Britain.

*Great Britain*

This comprises of three(3) countries of England, Scotland and Wales. Though they are politically seen as not individually sovereign states but they still maintain some level of independence where one can either decide to still be part of the union or be free from it.

*United Kingdom*

United Kingdom is a Union bringing together Great Britain and Northern Ireland, thus it is politely referred to as 'The United Kingdom of Great Britain and Northern Ireland'. 

I know it might seem difficult here to understand but let me break it further, United Kingdom is simply when you add the nation of Northern Ireland to Great Britain(England, Scotland and Wales) and they now amounts to four(4) countries.

Most times people get confuse when it comes to politics you won't hear that this is the president of England but when it comes to social event like football, you will hear England vs Spain, England vs Nigeria etc..  So people tend to be confuse if England is actually a country or something else, but let's digest it that England is a country but politically does not have a president and shares the same government governed by a Prime Minister, known as the British Prime Minister..

Someone from England is called an English man or woman.

Someone from Britain is called a Briton.

*photo* - England is boldly shown while the pink marked is Scotland and Wales alongside Northern Ireland. Republic of Ireland is gray.

Northern Ireland is that pink marked landmass at the top of gray marked Republic of Ireland.