Is all pasta made from the same dough?

No. There are at least 2 types. Those with, and those without eggs.

Different flours, eggs or no, different liquids (puréed spinach, beets, carrots, or perhaps squid ink) different spices, different oils, so…no.

OK. Thanks.

The people above are correct, but many pastas are the same dough.

Dry Italian pasta that you buy in the supermarket is almost always made without egg, there are exceptions. Homemade pasta, and fresh pasta almost always is made with egg.

The different size and forms of pasta change the taste and texture of the pasta dish. A capallini has more of the sauce flavor, because there are many more surfaces for the sauce to cover than a thicker pasta like fettuccini. The thicker pastas can be al dente, which changes the bite and flavor too. It’s minor differences though.

No, there are many types of different kinds of dough ingredients used for many different kinds of pasta.

You can read about some of those differences here: https://www.finecooking.com/article/which-flour-is-best-for-pasta

Some pasta recipes use egg, and others do not. You can read about why here: https://www.chowhound.com/post/pasta-question-add-egg-needed-929815?page=2

There are some differences between traditional Asian noodles, and traditional Italian noodles too: https://www.clearspring.co.uk/blogs/news/12237057-the-difference-between-noodles-pasta

And there are different ingredients within the genre of Asian noodles too: http://www.takepart.com/article/2014/05/14/cooking-asian-noodles

Many (but not all) Asian noodles are naturally gluten free: https://www.glutenfreeandmore.com/issues/4_18/gluten_free_noodle_asian-2764-1.html

And here is some scientific info regarding different types of pasta: https://www.sciencedirect.com/topics/food-science/noodles

Glad I asked!

^^ I’m glad you did too. Now who is hungry?

Me. But I’m eating peanut M&Ms.