The filling used to be just ricotta cheese, or spinach, but now the sky is the limit. Usually served with very simple sauces, as the interest is inside the pasta.
Ravioli pasta shouldn’t be confused with Neapolitan Ravioli. In Naples, they make a huge, square pie filled with spinach and ricotta, which is served in slices, and also called Ravioli.
Cook no more than directed by recipe or package, as will fall apart after that.
Other stuffed pasta such as Tortellini.