I'm only speaking for the US because accross the pond is different but 220 or 230 or 240 is what kind of plug you would have at a dryer or stove. It would big and 3 or 4 pronged. All other outlets in your house would be 110 0r 115 or 120. It all depends on who you ask. The difference is that a 110 has one hot wire and a neutral and a 220 has two hot wires and a neutral or ground or both. The difference in numbers I gave like 110 or 115 or 120 is basically people assuming voltage drops. Most of the time in a house you will see a little less than 120 volts which is what is supposed to be being supplied. So a 120 volt device will operate properly from 110 up to 120. Then if you added another hot leg it would double what ever measurment you used. So 110/220 or 115/230 or 120/240. I hope that helps. Unless your going with a serious grow setup I would stick to 110 because of availability and simple hookup.