Ice Cream is more complex than you might think.
Ice cream is made from water (in the milk), milk and cream, sugar, flavourings and some additives to help maintain the stability of the frozen structure to a degree of change in temperature.
There is some good information on the structure of ice cream here ; http://www.uoguelph.ca/foodscience/dairy-science-and-technology/dairy-products/ice-cream/ice-cream-structure