That's the typical process but it isn't a golden rule. What is a golden rule is that you don't just dump sauce on top of pasta. The sauce must be tossed with the pasta, and almost always a good few tablespoons of the pasta water is added, not just to loosen the sauce but also to make the sauce and pasta bind together via the starchiness of the water.

Other golden rules:

There is no such dish in Italy as spaghetti bolognese.

There is no such dish in Italy as spaghetti meatballs.

There is no cream in carbonara.

There is no pineapple on pizza.

Dried basil is not used in Italy.

True bolognese rágù never contains garlic, oregano or basil.

All rules are there to be broken...