A lacto-ovo vegetarian is a vegetarian who does not eat beef, pork, poultry, fish, shellfish or animal flesh of any kind, but is willing to consume cheese, butter, yogurt and eggs. Lacto- means "milk" and ovo- means "egg".In the Western world lacto-ovo vegetarians are the most common type of vegetarian. Generally speaking, when one uses the term vegetarian a lacto-ovo vegetarian is assumed. Lacto-ovo vegetarians are often well-catered to in restaurants and shops, especially in Europe and metropolitan cities in North America.Some lacto-ovo vegetarians who are motivated by ethical reasons may avoid fertilized eggs as well as caviar, feeling that both involve the killing of beings or torture and exploitation of source animals. They avoid cheese that contains rennet and yogurts that contain gelatin as these two things involve killing.In contrast, a vegetarian who consumes no animal products is called a vegan.In the airline industry a lacto-ovo vegetarian meal is known by the acronym VLML.