A herb is a plant grown for culinary, medicinal, or in some cases even spiritual value.
The green, leafy part of the plant is typically used.
General usage differs between culinary herbs and medicinal herbs.
A medicinal herb may be a shrub or other woody plant, whereas a culinary herb is a non-woody plant.
By contrast, spices are the seeds, berries, bark, root, fruit, or other parts of the plant, even leaves in some cases; although any of these, as well as any edible fruits or vegetables, may be considered "herbs" in medicinal or spiritual use.