Ireland shares many features with Great Britain.
Ireland . In 2011 , the population of Ireland was about 6.4 million , ranking it the second-most populous island in Europe after Great Britain . The culture of the island also shares many features with that of Great Britain , including the English language , and sports such as association football , rugby , horse racing , and golf . United Kingdom . Lying off the north-western coast of the European mainland , the United Kingdom includes the island of Great Britain , the north-eastern part of the island of Ireland and many smaller islands .