What's the difference between marinara sauce and spaghetti sauce, and how do they vary in terms of ingredients and flavors?

Marinara sauce is a simple tomato-based sauce with garlic, herbs, and olive oil, while spaghetti sauce is a more complex sauce that may include meat, vegetables, and additional seasonings. Marinara sauce tends to be lighter and fresher in flavor, while spaghetti sauce is richer and heartier.