The proper name of the latte coffee drink is actually "cafe latte," from the Italian meaning, "coffee and milk." However, there are ways to make espresso drinks that are very similar to the traditional latte, but without cow's milk.
The standard coffee shop latte is milk, steamed to 160 degrees or less, with the steam wand of an espresso machine. The milk is poured into a cup containing fresh espresso shots. The latte is topped with a relatively short layer of velvety foam, to meet the lips.
Soy, almond and lactose-free "milks" can all be delicious alternatives to a cow's milk latte. You may want to ask for the soy to be steamed "a little less hot," as it scalds easily and alters the flavor.
An Americano is made in a similar way to the latte, but with hot water instead of milk. Hot water is added to a cup, and then espresso shots are added. The drink was dubbed the "Americano," because American tourists wanted to dilute their espresso shots to the flavor intensity and size of a cup of drip coffee. It still retains the flavor of espresso, like a latte retains the flavor of espresso, except without milk.