The term Italian dressing ingredient refers to three items commonly used in the preparation of Italian dressing: OREGANO, olive oil, and salad oil. OREGANO is a fragrant herb with a strong flavor, often used in Italian cuisine. Olive oil is a type of vegetable oil made from olives, and is a staple in Mediterranean cooking. Salad oil is a type of vegetable oil used for salads and other dishes. All three ingredients are essential components of Italian dressing.