gelato is an Italian word that means exactly "ice cream". Or rather, since ice cream was made in Italy earlier than in England, it is ice cream which means "gelato"...
It is not a special type of ice cream that you can find only in Italy. The word comes from the adjective gelato which means "frozen, extremely cold".
In other countries, though, there is a difference between ice cream and gelato; for an interpretation and analysis of that difference, read anthropod's writeup.