What is the difference between Ireland and Northern Ireland?

Sometimes it is difficult to distinguish between Ireland and Northern Ireland , for the simple reason that both countries are on the same island and have almost the same name. However, these are two different countries.
Ireland is a country in its own right and a Republic . Its capital is Dublin. Northern Ireland is a nation that is part of the United Kingdom . Therefore, it does not have a president and depends on the constitutional monarchy of England. Its sovereign is, in fact, the Queen of England.
The Giant’s Causeway is located in Northern Ireland.

But why is the island of Ireland divided in two?: What is the difference between Ireland and Northern Ireland?

This situation is due to the history of Ireland. In the Middle Ages, Ireland came under English rule. Although there were numerous attempts by the Irish to regain their independence.
A war for independence broke out between 1919 and 1921, in which the United Kingdom ended up ceding part of Ireland to the Irish. Southern Ireland officially became the Republic of Ireland in 1949 and broke any English rule.
The rest of Ireland became Northern Ireland, a nation that is still part of the United Kingdom today. This situation continues to affect the northern population today. A minority of Christians want the two Ireland to unite and get rid of all English rule, while a majority of Protestants say they want to stay in the UK.
As you can imagine, the two countries are marked by a big difference: religion . Protestants are ubiquitous in the north, while Christians are the majority in the south. However, that is not the only difference, since the same currency cannot be used in both countries either.
Northern Ireland uses sterling while Ireland uses the euro.
At present, the situation between the two countries is still quite complicated; in particular, in , where a civil war broke out in 1968. The various clashes caused a total of 3,500 deaths. One of the most significant events of all that was  Bloody Sunday , in which thirteen Christian protesters were killed by British paratroopers.
Peace could be found on April 10, 1998 with the signing of the Good Friday Agreement. However, the situation remains fragile and recent events related to Brexit have shown once again that the issue of the border between the two Ireland remains too hot a topic on the island.