What exactly do they put in vegetarian cheese?

My dad and I, we can't eat any dairy products, because we have allergies and get migraines when we use such things, but when we ate the vegetarian cheese, it really did not taste different.

Well, if you can't have any dairy products, then you can't be eating cheese, even the vegetarian kind.
Vegetarian cheese is made with milk, same as ordinary cheese, it's just that it has non-animal rennet in it, instead of the kind made from the stomach of slaughtered calves.
However, maybe you mean vegan cheese. That has no dairy ingredients. As an example, here are the ingredients of one vegan cheese:

Vegan Gourmet 鈩?Mozzarella Cheese Alternative

Ingredients: Filtered Water, Expeller Pressed Canola Oil, Tofu (Soybeans, Calcium Sulfate), Soy Protein, Inulin ( A Natural Extract of Chicory), Carrageenan (from Seaweed), Agar Agar, Sea Salt, Natural Flavor (Vegan), Calcium Lactate (Vegan), Lactic Acid (vegan).

hey:
vege cheese is supp to have no animal product or casein!just check the nutri contents.
sanam

ps:depands on the brand of the cheese

Alot of the non-dairy cheese substitutes have casein and other dairy derivitives in them to retain taste and the ability to melt and stretch. They are primarily for people who are lactose intolerant. Vegans still can't eat them. There are vegan soy cheeses that have no dairy derivitives and they are gross! (my personal opinion on that part!)

Mostly, its made from soy and nutritional yeast. You can make a great mock cheese sauce with nutritional yeast (not brewers or bakers yeast). I am allergic to soy, so I avoid it. If you have allergies to commercial milk, try raw milk. Most allergies are to the growth hormones, antibiotics, and steroids in commercial milk. The vitamin D added to milk is a steroid. I am highly allergic to commercial dairy, but do just fine on raw. Google rawmilk.com for more info

I don't care for vegan cheese. It's waay to processed and think it was making me break out. So I stopped eating in. Your're better off making it from scratch with yeast or something

That's blasphemy! A cheese is a cheese is a cheese