Culinary herbs are distinguished from vegetables in that, like spices, they are used in small amounts and provide flavor rather than substance to food.
Herbs can be perennials such as thyme or lavender, biennials such as parsley, or annuals like basil. Perennial herbs can be shrubs such as rosemary, Rosmarinus officinalis, or trees such as bay laurel, Laurus nobilis – this contrasts with botanical herbs, which by definition cannot be woody plants. Some plants are used as both herbs and spices, such as dill weed and dill seed or coriander leaves and seeds. Also, there are some herbs such as those in the mint family that are used for both culinary and medicinal purposes.