Complex sentence: It is difficult to define what is meant by the term "salad"; many salads use raw ingredients, but some salads use cooked ingredients, and most salads use vegetables, but such things as fruit salads also exist.
Split into simpler sentences: It is difficult to define what is meant by the term "salad", as it encompasses a wide array of serving styles and options. Though many salads use raw ingredients, some use cooked ingredients; most salads use vegetables, though fruit salads also exist.