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.