In the culinary arts, a spice is a seed, fruit, root, bark, or other plant substance primarily used for flavouring or colouring food. Spices are distinguished from herbs, which are the leaves, flowers, or stems of plants used for flavouring or as a garnish. Spices and herbs are both seasonings. Spices are sometimes used in medicine, religious rituals, cosmetics, or perfume production. They are usually classified into spices, spice seeds, and herbal categories. For example, vanilla is commonly used as an ingredient in fragrance manufacturing. Plant-based sweeteners such as sugar are not considered spices.