Everyone has some form of tradition that is passed though generations of families, most of which we never bothering exploring.
Northern Ireland and the Republic of Ireland have different currencies.
In the Republic of Ireland the currency used is the Euro and in Northern Ireland the currency used is the Pound Sterling.
Most visits to Ireland are trouble-free but you should be aware of the global risk of indiscriminate international terrorist attacks, which could be against civilian targets, including places frequented by foreigners.