Often people don't really investigate the various types of vegetarians, but instead lump them under the "Vegetarian Umbrella". The diets actually differ in rather significant ways, catering to a wide range of health concerns and religious practices. While the foundation of these lifestyles may consist of an abundance of fruits & vegetables, there are critical distinctions valued by each group. Some allow dairy and fish on to their plates, while others exclude even highly nutritious vegetables from their diets.
Lacto-ovo vegetarians are the types of vegetarians most think of when discussing vegetarianism. This group refrains from consuming any pork, beef, poultry, fish, or flesh of any kind, but will eat dairy & eggs.
The Lacto-Ovo brand of vegetarianism is the most common in North America, and usually the assumed brand when someone says "vegetarian". In more recent years, they have been the most catered to socially.
There are also lacto vegetarians, who will eat dairy products, but not eggs. And naturally there are ovo vegetarians that will consume eggs, but not dairy.
Vegans are those types of vegetarians that are politically and ethically opposed to the slaughter, exploitation, testing, or abuse of animals.
No animal products or derivatives are consumed by this group, and often this principle extends to other areas of life also.
Raw vegans consume foods in their natural state, with very little processing or heating. Fruits and vegetables are generally not heated above 118 degrees to preserve the foods' nutritional value. Although, "cooking" in the conventional sense of the word is avoided, some raw vegans dehydrate food to alter the texture. There are some pretty creative and delicious dishes within this lifestyle, even though there's limited heating and processing.
The term "flexitarian" best describes those who are transitioning into a vegetarian diet, as well as those who may mainly eat vegetarian, but occasionally choose to consume meat, dairy, or egg products.
Motivated by religious beliefs, these types of vegetarians mostly consume vegetables, fruits, grains, seeds, etc. However, they are encouraged not to eat root or tuber vegetables.
Jains adhere to a lifestyle of non-violence, both directly and indirectly. Uprooting the (root) vegetables violates the principle of "Ahimsa" (literal translation: non-injuring).
Traditionally, Jain vegetarians include dairy in their diets, but questionable dairy farming practices have pushed many to opt for a vegan diet. If dairy (specifically milk & cheese) is consumed, it must be prepared freshly on the day it is eaten.
Honey is also prohibited because it is the waste of bees. Eggs are also excluded from the diet due to the fact eggs are considered offspring of animals.
Naturally, most assume fruitarians just eat fruit. Well, it's not that simple.
Most consume fruit, plant matter, nuts &seeds. The fruit and plant matter, however, are limited to those foods that can be collected without harming the plant.
We must also remember that many foods most consider vegetables are really fruits, like tomatoes and cucumbers, or even peppers.
Pescatarians exclude most animal flesh from their diets, with the exception of fish. Usually, fish is included, not just for taste, but for it's ability to promote optimal health.
Fish provides very important fatty acids (Omega-3s)that can significantly boost your quality of health. However, there are ways to consume these fatty acids within a plant-based diet, for example hemp milk provide the perfect ratio of Omega-3 to Omega-6 fatty acids.