This is where all American pizza starts, the traditional pizza imported from Naples, Italy. Neapolitan-style pizza dough uses ultra-fine flour and is allowed to ferment for a few hours to a few days before being rolled out, topped, and pushed into an oven blasting along at 900℉ for just a minute or two. The end result is a slightly charred, doughy crust with a tart, lively sauce, mozzarella cheese, and a splash of basil (plus anything else you want) on top.

New York-style pizza started off life as a variation of the Neapolitan, but it’s grown to become an entire category of pizza style. Ranging from the $1 slices you can pluck from just about any corner of the city to more elevated offerings in sit-down restaurants, this pizza style is lighter on sauce, heavier on cheese, and is served in large slices that are designed to be folded up and eaten one-handed. Toppings choice varies by taste, but there are some variations within the New York-style worth noting. Brooklyn-style pizza has a closer balance between sauce and cheese, as well as a crispier crust. Buffalo-style pizza, which dispenses with the concept of a “crust” and simply extends the cheese and toppings to the edge, uses a sweeter sauce than traditional New York-style, and it uses cup-and-char pepperoni exclusively (the kind that curl up and blacken).

A square pie with a thick, spongy dough with a crispy, slightly charred base, the traditional Sicilian excludes the mozzarella in favor of lots of sauce and minimal toppings. Modern variations include cheese and can even go heavy on the toppings, but it’s that delightfully thick dough that makes or break this style. Increasingly you’ll also encounter the “Grandma” variation, which is a square pie inspired by the pizza Italian grandmas made at home using whatever ingredients they had. The dough is thinner, and puts the cheese on first and then the sauce, keeping it crispier.

One of the most famous pizza styles in the world, this is a pan-baked pizza that is often derided as something other than pizza (a quick way to insult a Chicago-style pizza is to call it a casserole or a quiche). The thick dough is covered in cheese, then sauce (which is baked off as it cooks). The crust is usually oiled or buttered to get it nice and crispy, and it’s a pizza you more or less have to eat with a knife and fork. Some restaurants cover the whole thing with dough, turning it literally into a pie (sometimes called a “stuffed” pizza), but it’s essentially the same thing.

This Midwestern variation uses brewer’s malt in the dough, which gives it a sweeter taste and a darker color. The sauce will be notably spicier than most other styles, and it is traditionally served with a pork sausage that goes heavy on fennel—and is typically piled on thick and all the way to the edge. Then the pizza is cut into long strips using scissors, which is a lot more common than you might think. This is a prime example of a regional pizza style that needs to be a lot more common.

Making a St. Louis pizza is like making a pizza using crackers. The crust is unleavened, and thus incredibly thin and crunchy. The sauce is sweet, but what really sets this pizza apart is the exclusive use of Provel cheese, which is a mix of cheddar, Swiss, and provolone and more or less specific to the St. Louis area. Provel has a very distinct flavor, and a very low melting point, making a St, Louis-style pizza a gooey, messy (but delicious!) experience.

If you’re in certain areas of New England, you will hear people order apizza (pronounced more or less “ah-peets”), and even see restaurant signs offering it. It’s just a play on how Italian immigrants pronounced pizza that’s become a regional mainstay. A New Haven-style apizza has a charred, blistery, irregularly-shaped crust that’s really chewy, while the sauce resembles New York-style pretty closely. The pizza will often come dusted with pecorino Romano cheese, and because it’s New England, it’s not at all uncommon to find these pizzas topped with seafood. In fact, the most famous example of a New Haven-style pizza is the White Clam Pizza found at the legendary Frank Pepe Pizzeria Napoletana. Clams? Yes, dammit, clams. Along with mozzarella, garlic, oregano, and a touch of olive oil. Chances are when people reference a New Haven-style pizza, they’re thinking about the clam pie. And now you’re thinking about the clam pie. You’re welcome.

Originally cooked in square steel pans taken from auto factories (no, really), the Detroit-style pizza resembles a Sicilian-style pizza with a fluffy dough covered in insane amounts of Brick Cheese. Sauce is then added on top, and the whole thing is baked. The cheese melts into the dough and caramelizes on the outside, resulting in a thick square slice that is satisfyingly crispy. It’s a simple recipe that produces a truly distinct regional pizza style.

I know I specified that we’re not talking about toppings choices here, but the California-style pizza is entirely defined by its toppings, so it’s kind of the exception that proves the rule. Sometimes this is also called a “Chef” pizza, because it’s all about fresh, local ingredients that change with availability by season. Basically, if you never imagined it belonged on a pizza, yet there it is on top of your otherwise normal-looking pizza (or if you’ve seen it on the menu at the California Pizza Kitchen), it’s probably considered a “gourmet” or “California-style” pizza. For example, smoked salmon and capers? Barbecue chicken? Lobster? That’s a California pizza, my friends.

Specific to Old Forge, Pa. and nearby areas, this style of pizza arrives in a square sheet pan and sports an onion-heavy sauce. The crust is chewy and soft, and the cheese varies literally from shop to shop—there are no cheese rules here. The red version has your standard sauce/cheese balance, but the white version of the Old Forge is essentially a stuffed pizza (with a layer of dough on top).

With a super-thick, braided crust and tons of toppings (just about any kind you can think of is available—and allowed), this is a dense, chewy pie that will give your mouth muscles a workout. The crust is what sets it apart—not only is it substantial, it’s traditionally left to last, then dipped in honey or other sweet condiments as a sort of instant dessert.

A tomato pie disdains cheese in favor of a thick, focaccia-style crust topped with a thick smear of sauce. There are three major variants of a tomato pie: A Philly Tomato Pie is square and usually served room temperature (or even cold), with (at most) a dusting of Parmesan on top—often you don’t see any cheese at all with this variant. The Trenton Tomato Pie is round and embraces cheese, but the cheese goes first, with a generous application of sauce on top. The sauce bakes up in the oven, thickening into a sort of tomato-y crust of its own.

Then there’s the Rhode Island-style “red strips.” These are...weird. Sometimes called “bakery pizza” (because they’re served in bakeries, which does not inspire confidence) they don’t use traditional pizza dough. Instead, this is basically focaccia bread with tomato sauce on top, cut into long strips and served cold.

Ohio has two distinct styles of pizza, which is probably surprising to anyone who doesn’t actually live in Ohio. The Ohio Valley-style pizza is distinguished by the fact that the cheese and toppings are added after the pie has emerged from the oven, and rely on the heat of the pizza itself to warm them up. Traditionally, these pizzas also use provolone cheese instead of mozzarella. The Dayton-style pizza has a thin, cracker-like crust, and is marked by toppings portions that can best be described as “liberal.” In other words, when a Dayton-style pizza is served, you can’t even see the cheese for all the toppings on it.

This is a relatively new variant in the modern world, but a welcome one that can be defined with two simple words: deep fried. Essentially a Neapolitan pizza, the deep-frying of the dough gives it an almost donut-like consistency. This is actually an old style of pizza making a comeback—it used to be a way of using leftover dough and ingredients to whip up an economical meal back in Italy. Today the fried dough is baked in the oven like a traditional pizza, which makes it extra crispy.

Don’t get confused! Your local pizza joint might offer a “Greek” pizza that sports stuff like black olives and feta cheese, but a Greek-style pizza is much more than some specific toppings. This round pizza sits in-between deep-dish and New York-style, using an oiled pan to create a fluffy, airy dough. It then applies an in-your-face sauce that is packed with seasoning (typically oregano is a star here) and a very thick combination of cheeses. It’s found mainly in New England, where Greek immigrants often set up diners and offered the dish on their menus.

First, let me assure you this is a real pizza style that exists. Found mainly in Pennsylvania, this pizza style is simple: Take a Sicilian-style crust, top it with some sweet sauce, toss on a slice of deli salami and a bell pepper—then slap on a slice of American cheese or Velveeta. While the whole square-of-yellow-cheese-product might put you off, the fact is this is a delicious slice of pizza—and in a world where regional differences are being scoured away, a welcome blast of culinary weirdness.

Yes, most people don’t consider this to be authentic pizza, but it is a legitimate variation on the form, like it or not. It’s all in the name: Take a loaf of French-style bread, slice it in half, toast it up, then slather it in sauce, cheese, and toppings and bake. It’s certainly a different experience due to the flavor and texture of the bread, and has the advantage of being a form of pizza you can whip up in your own kitchen without any special tools, ingredients, or knowledge.

You can find a “white” version of many pizza varieties, but pizza bianca is a whole different breed of pizza. Very often, a pizza bianca comes without any sauce or cheese or toppings—it is essentially pizza dough baked and then drizzled with some oil and salt. You can argue it’s “pizzaness” if you want, but it comes directly from Rome. This stuff is best eaten fresh from the oven.

Roman-style pizza comes in two basic forms. Al taglio (“by the cut”) is baked in a rectangle sheet and is sold by the pound, cut with scissors. The dough is denser and crunchier than most other styles of pizza, and the approach to toppings is chaos—you can find just about anything on an al taglio pizza. The tonda-style Roman pizza is a round pie with a crust so thin and light you really can’t eat it with your hands.

Called a tavern cut (or “tavern style”) because it originated in pubs and bars as a cheap or free food for the boozehounds, this is a round pie cut into square slices sporting a paper-thin crust. It’s usually baked in a shallow pan, then transferred to the hearth for crisping. It’s intended to be a snack more than a meal, and its flavor will vary depending on just how long you’ve been in the bar—but this style of pizza is starting to show up in elevated form in fancier restaurants.