Dairy milk
Milk, according to traditional meaning, is a white liquid produced by female mammals. Since it comes from an animal, vegans do not consume any milk or dairy products in any form. Vegetarians do.
Fortunately, milk can be easily replaced by similar liquids made out of plants, and there are many kinds of such milk substitutes.
Milk from a cow or goat are the most common available commercially in European\Western cultures. Sheep and buffalo milk are widely available in many Asian and African countries.
Health
Investigators found that a large amount of milk in a daily diet did appear to be linked to an increased risk of death in both men and women during the study period. In addition, excessive milk drinking appeared to actually increase a woman's risk of broken bones, compared with women who drank little milk.
Production
Commercial dairy farming using automated milking equipment, produces the vast majority of milk in developed countries.