If you are unsure if you need a Visitor Visa or another type of Irish visa for your unique circumstances, you may wish to consult with a qualified immigration adviser such as at Total Law. There are a number of visa types for different situations, including a transit visa for those just passing through Ireland who is from a visa required country. Certain countries may be entitled to visa-free travel. If you intend to stay in Ireland long term, you may need a residence permit.