Water ices and sorbets (a.k.a. “sorbetto” when presented for sale/consumption alongside gelato) can be considered sherbets without dairy ingredients. Water ices are compositions of water, sugar, corn syrup, and color/flavor. Sorbets are “upscale water ices” using fruit primarily as the source of solids.
Sometimes produced as quiescently (without stirring) frozen novelties, sometimes aerated, it should be noted that of the categories “water ice,” “sorbet” and “Italian Ice,” only “water ice” has a standard of identity. In this case, the standard specifies that no dairy is allowed. Here ends simplicity.