There has been a bit of discussion under the picture of flatbread cooking, and I thought I'd bring up a few things here since I love to talk about flatbread.
The point of a tandoor is to cook a lot of bread (or meat) quickly using relatively little fuel. You build a hot fire in the oven to heat it, then when it is hot enough, you slap all your bread onto the sides of the oven. The loaves take around 5-8 minutes to cook. When they're done cooking, they fall off and the baker fishes them out with long tongs-like things. Of course, many people today buy their bread from a baker and the fuel-saving properties of a tandoor aren't as important.
Naan is usually made with yeast, but there are many different variations. It's eaten all over Central Asia. There are other tandoor breads, but naan is generally specific to Central Asia. One of my favorites is an Afghan one made with yogurt. Central Asian naan often has a thicker ridge around the side where it isn't stamped. The designs on the bread are also traditional. I've been looking for bread stamps so I can quit using a fork to make designs in the US.
There really are a huge variety of flatbreads from around the world, from the familiar tortillas and bannocks to roti and lavash in Asia. The Bedu' in the Middle East make unleavened flatbreads that are somewhat similar to lavash, although not as large. And not quite as thin. They cook them on a convex surface over a hot fire. I've had some success making it on a wok turned upside down.
I usually make naan in the US on a stone (like some people use for pizza). Since tandoor ovens start off very hot, you want to replicate that. I preheat my stone for an extra 10 minutes before I slap my bread on. The bread comes right off the stone when it is cooked, just like in a tandoor. The stone really does a pretty good job of replicating tandoor ovens. You can also use unglazed pottery tiles and line the lowest rack of your oven with them. Just leave a 1-inch space around all the edges to allow air circulation.
My older son's favorite flatbread is batia roti, from Rajasthan in India. It is salty and filled with cumin and absolutely delicious. There are all kinds of flatbreads and toppings all over this part of the world. I love being in a flatbread place!