1. A vegetarian is someone who lives on a diet of grains, pulses, nuts, seeds, vegetables and fruits, with, or without, the use of dairy products and eggs.
2. A vegetarian does not eat meat, poultry, game, fish, shellfish or crustacea, or by-products of slaughter.
In addition to these definitions, there are also different forms of vegetarianism. Below are the 4 most common and links to sample diets for each.
Lacto-Ovo-Vegetarian
This is the most common form of vegetarianism in the United States. The term stems from the Latin lac,meaning milk and ovum, meaning egg. That being said, this form of vegetarianism consists of a person who does eat both dairy and milk products. Since it is the most popular form in Western society, most restaurants tend to cater to this diet style. While Lacto-Ovo Vegetarians do consume eggs, they only do so if the eggs are free-range eggs meaning that they are produced by birds who are allowed outdoors during the day. You can review a sample eating plan for this diet at the National Heart, Lung, and Blood Institude website.
Lacto-Vegetarian Diet
This diet consists of a person who eats dairy products but does not eat eggs. This diet is popular Eastern religions such as Hinduism, Sikhism, Jainism, and Buddhism because they place a value on all living beings. This diet is usually refrains from eating cheeses with rennet (curdled milk from the stomach of a calf not accustomed to food outside of mother's milk) and yogurts that contain gelatin. You can find a sample of this type of diet at the Vegetarian Love To Know webpage.
Ovo-Vegetarian
This diet allows for the consumption of eggs but does not consume any type of dairy products. Most people who follow this diet do so because of the practices and slaughtering of cows and calves. These practices include constantly keeping cows pregnant so that they will continuously produce milk and also the slaughtering of male calves. In addition, the practice of separating a calf from it's mother. Another reason that some choose this diet is because of the fact that they are lactose intolerant. You can find a sample of this diet on the Livestrong website.
Vegan
Vegans do not consume any dairy, eggs, or any product by animals at all. The Vegan Society states that "Veganism is a way of living which seeks to exclude, as far as is possible and practicable, all forms of exploitation of, and cruelty to, animals for food, clothing, or any other purpose." This diet style differs from the others because it goes beyond just avoiding certain foods. It can stem types of clothes and even medication. Some vegans ask their doctor for prescriptions to medication that do not include any animal products or that have no been tested on animals. You can find a sample of this diet at PETA website.