These two ingredients are quite similar, but have differences in both the way they are made and the way they are used in recipes. Tomato paste is richer and a little sweeter because it's so concentrated, and it's cooked for longer. Seeds and skins are removed to achieve the rich flavor. Tomato puree is milder, with a fresher, lighter texture and flavor. All parts of the tomatoes are used, and the tomatoes are cooked just lightly. This keeps the flavor more in line with fresh tomatoes.