Herbs are any plants "with leaves, seeds, or flowers used for flavoring, food, medicine, or perfume" or parts of "such a plant as used in cooking".(In botanical use in the USA, the term "herb" is often employed differently, for any non-woody flowering plant, regardless of its flavor, scent or other properties, and thus includes only grass-like plants and forbs.)
Herbs have a variety of uses including culinary, medicinal, and in some cases spiritual usage. General usage differs between culinary herbs and medicinal herbs. In medicinal or spiritual use any of the parts of the plant might be considered "herbs", including leaves, roots, flowers, seeds, resin, root bark, inner bark (and cambium), berries and sometimes the pericarp or other portions of the plant. Culinary use of the term "herb" typically distinguishes between herbs, from the leafy green parts of a plant (either fresh or dried), and spices, from other parts of the plant (usually dried), including seeds, berries, bark, root and fruit.