The reason why bolognese is not Italian is because of the combination of spaghetti, which is a Southern Italian dry pasta, with ragu alla bolognese , which is a Northern Italian meat sauce is considered to be a culinary mismatch by Italians.
Instead though the rich meat sauce, or ragu is served historically with fresh, egg based pasta, such as tagliatelle, which is also typical of the Bologna region.
The spaghetti bolognese is a food that evolved from Italian American food traditions, which combine the elements from different Italian regions, which do not go together traditionally.
The ingredients that are in authentic bolognese are a soffritto of finely diced onions carrots, celery, pancetta, a mix of ground beef and pork or even just beef, dry white wine, a small amount of tomato passata or puree, and whole milk, which is then slowly cooked with minimal amount of seasoning beyond salt, pepper and sometimes a bay leaf or nutmeg.
The bolognese sauce is also simmered for several hours, to develop a rich, tender texture and it's then served traditionally with fresh tagliatelle.
The difference between bolognese sauce and regular spaghetti sauce is that regular spaghetti sauce is any type of sauce that is served with spaghetti.
And bolognese sauce is made with ground or minced meat, like beef or pork as well as a mix of vegetables such as carrots, onions, celery, wine, which is often white wine and dairy such as cream or milk and has only a small amount of tomato in the ingredients.
Generic spaghetti sauce can be a simple tomato and garlic sauce also known as marinara, a creamy sauce, or a tomato based meat sauce which lacks the specific ingredients and slow cooked complexity of authentic Bolognese sauce.
Bolognese sauce, which is known in Italian as ragù alla bolognese or ragù bolognese, is the main variety of ragù in Italian cuisine.
Bolognese sauce is associated with the city of Bologna. Ragù alla bolognese is a slowly cooked meat-based sauce, and its preparation involves several techniques, including sweating, sautéing, and braising.
Spaghetti sauce can refer to many different sauces made primarily from tomatoes.
In some countries the term spaghetti sauce refers to a sauce to be served as part of a dish; in others, it is a condiment.
Spaghetti sauce is essentially a version of a marinara sauce.
Spaghetti sauce usually contains added ingredients such as ground beef to make a bolognese sauce.