Ricotta means “recooked” in Italian.  It’s a fresh cheese made from cow, goat, sheep, or Italian water buffalo whey leftover from cheese making after curd gets strained out; most American ricottas are cow-based.  Italian ricottas come in many varieties and some are even protected by law. Milk can be added during production or replace whey in some cases, but the recycled whey is what gives ricotta its name.