The healthcare system in Ireland is not straightforward to explain but suffice to say, it is very accessible for those who are legally resident in the country. Put simply, anyone who is living in Ireland on a permanent basis is entitled to healthcare. For a certain percentage of the population, this will be entirely free. For everyone else, there are some fees involved, although these are low thanks to government subsidies.
Having access to affordable healthcare is a major bonus, and is not a guarantee in every country. In the USA, for example, you must arrange your own private health insurance. This can be expensive, and certain medical issues might not be covered by the policy.