Some people have specific diets which restrict them from consuming or using certain products. An example of one of these people is a vegetarian.
A lacto-vegetarian is not allowed to eat meat, like other types of vegetarians. However, a lacto-vegetarian is not allowed to eat any eggs and cannot drink milk. Not much in their diet provides them protein, which they need.
A lacto-ovo vegetarian is only not allowed to eat any meat, fish or poultry, like other types of vegetarians. Unlike a lacto-vegetarian, a lacto-ovo vegetarian is allowed to eat other products such as eggs or milk. Eggs and nuts is where they most get their protein from.
A pescetarian is not allowed to eat any meat or poultry, like any other vegetarian. However, unlike a regular vegetarian a pescetarian is allowed to eat fish. Pescetarians get most of their protein from fish and eggs.
A vegan is the most extreme type of vegetarian. They refuse to eat any meat, poultry and fish like a normal vegetarian. Additionally, unlike a vegetarian they also refuse to use any products that originated from an animal. For example, these products could be leather shoes, eggs or even wool.