The main difference lies in their menu offerings and preparation styles. Captain D's tends to offer a wider variety of seafood, including grilled options and Southern-style sides, emphasizing a slightly healthier and more varied menu. Long John Silver's, on the other hand, is best known for its batter-dipped fish and chicken, with a focus on deep-fried items. Each brand has its own unique recipes and seasoning blends, contributing to a distinct taste and dining experience.