When we talk about milk and cream used in food service, we are nearly always talking about milk from cows. Milk from other animals, including goats, sheep, and water buffalo, is used to make some cheeses, but most of the liquid milk we see, except for a small amount of goat milk, is milk from dairy cows.
Milk is used as a beverage and also in cooking. Similarly, other milk products, including cream, butter, and cheese, are eaten as purchased and also used in cooking.