The kind of onion that is in spaghetti is yellow onions, due to the yellow onions ability to balance out the acidity of the tomatoes and to also caramelize to a sweet flavor when the onion is cooked.
Other good onions to use in spaghetti are sweet onions such as Vidalia as they don't require any pre treatment and have a naturally sweet flavor.
You can also use white onions for spaghetti as they are known for their crispiness and versatility, especially in Mexican inspired dishes.
Italians eat spaghetti with tomato based sauce, meat based sauce, seafood based sauce and even vegetable based sauce.
Spaghetti in Italy is often served as a first course or primo meal.
Italian spaghetti is also often also served with other side dishes like vegetables, bread or even salads.
To do as the Italians do when serving pasta, try serving a smaller portion of pasta as a primo for an Italian-inspired dinner party, or as precursor to a meat, fish or vegetable main.
The difference between American spaghetti and Italian spaghetti are that American spaghetti is about starch and meat with a tomato sauce.
Italian spaghetti on the other hand is the quality of the pasta and focuses on the tomato, each individual element is crucial.
Italian American is whole dish composition, Italian is appreciating the components.
In Italian tradition, pasta is seasoned by the sauce itself -- no such thing as inherently ``tasteless'', since if done right the pasta gets all the salt & flavor from the sauce.
And, good pasta from Italy truly lacks nothing in the texture & quality of ingredients department.