A very popular (perhaps the most popular, at least in Rome) form of coffee in Italy.
It comes in two forms:
Standard cappuccino, made from coffee (espresso) with the froth of steamed milk, served in a coffee cup with a handle. It is typically prepared for you by a professional barista in front of your eyes. You add your own sugar to make it as sweet as you like.
While in America people often mix flavored syrups with it, I have never seen anyone do that during my four years in Italy (and it would probably be considered sacrilege).
Cold cappuccino, only served during the hot summer months. I only had it a couple of times (mostly because I generally took a vacation outside of Italy during summer months).
However, the few that I had were indeed the perfect summer drink. In this case, the barista had already made the coffee beforehand, and had it stored in a refrigerator inside a metal pitcher. He poured the cold coffee in a tall skinny glass, about half full, then filled the rest with cold milk (not steamed). The first time I had it, I asked where the sugar was. The barista almost had a fit stating you do not put sugar in cappuccino freddo (cold cappuccino). So, I drank it unsweetened, and had to admit, he was right. It was delicious, and very refreshing in the summer heat of Rome!
By the way, the name cappucino is derived from the brown color of the habits (religious garb) worn by the Capuchin friars. I only know this tidbit because at the time I happened to be a Capuchin friar myself.