The community in Northern Ireland can be roughly divided into two groups:
Are mainly Protestants and have traditionally wanted Northern Ireland to stay part of the UK. They are also known as Loyalists (because they are loyal to the British crown).
Are mainly Catholics and have wanted the area to join the Republic of Ireland (the rest of Ireland) and form a united Ireland. They are also known as Republicans (because they want to be part of the Republic Of Ireland).
The differing views of the two groups led to a lot of unrest.