Dill seed and dill weed are two parts of the same plant, but they have different flavors and uses in cooking.
Dill seed is the mature seed of the dill plant and has a more intense flavor than dill weed. It has a slightly bitter, earthy taste with hints of anise and lemon. Dill seed is commonly used as a spice in pickling, as well as in breads, soups, and stews.
Dill weed, on the other hand, is the fresh leaves and stems of the dill plant. It has a more delicate flavor than dill seed and is often described as having a mild, sweet taste with hints of anise and parsley. Dill weed is commonly used as a garnish for fish dishes, in dips, salads, and dressings, as well as in potato dishes and with vegetables like carrots, peas, and beans.
In summary, dill seed has a stronger, more intense flavor and is commonly used as a spice, especially in pickling, while dill weed has a milder flavor and is commonly used as a garnish or herb in a variety of dishes.