Voltage is 220V AC, at 50Hz. Don't forget to check the ratings of your electrical items before bringing them with you to Ireland.
Wall socket and plug are shown below:
Most electrical items from the UK will work without any conversion necessary.
Most electrical items from continental Europe will work with a small, cheap adapter which can be purchased in most electrical and travel shops, and at most air and sea ports.
Most electrical items from the USA will not work in Ireland. Check the voltage ratings which should be marked on the appliance.