Spaghetti sauce is a tomato-based sauce that’s served over spaghetti. The traditional bolognese sauce is a meat sauce that is thicker and includes milk, which adds to the thickness and creaminess. Also, it contains just a touch of tomato. Outside of Italy, bolognese sauce has commonly been adapted as a tomato-based meat sauce. Many cooks have put a vegetarian or vegan twist on it, and I appreciate all the variations and creativity that people bring to the table.