❓How exactly do lacto-ovo vegetarian, vegan, fruitarian, and other categories break down?

Here's a quick rundown of the common categories, roughly ordered from least to most restrictive: lacto-ovo vegetarian means no meat, poultry, fish, or seafood, but eggs and dairy are fine — this is the most common type. Ovo-vegetarian eats eggs but not dairy; lacto-vegetarian eats dairy but not eggs. Vegan means no animal-derived foods or products at all, including eggs, dairy, and honey, and a lot of people extend that to avoiding leather, down, and other animal-derived materials too. Fruitarianism is a more extreme branch of veganism — eating only ripe fruit, nuts, and seeds, i.e. parts you can obtain "without killing the plant." This category is pretty controversial, since sticking to it strictly long-term can easily lead to nutritional imbalances. In China there's also "wu xin su" (five-pungent-free vegetarian), which combines religious precepts with avoiding scallions, garlic, chives, and similar alliums. Knowing these categories is mainly useful for communicating what you specifically don't eat — you don't need to stress about fitting neatly into one standard label, since a lot of people's actual diets are personal combinations of several categories.