A spice is a seed, fruit, root, bark, berry, bud or vegetable substance primarily used for flavoring, coloring or preserving food.
Oil seeds are crops which are grown primarily for the oil contained in the seeds.
Grains are small, hard, dry seeds, with or without attached hulls or fruit layers, harvested for human or animal consumption.
Herbs are any plants used for food, flavoring, medicine, or perfume. Culinary use typically distinguishes herbs from spices.