From Academic Kids
An herb (pronounced "urb" in American English and "hurb" in British English) is a plant grown for culinary or medicinal 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, or other parts of the plant, even leaves in some cases. Culinary herbs are distinguished from vegetables in that they are used in small quantities and provide flavor rather than substance to food.
In botany, an herb is a plant that does not produce a woody stem, or is a plant that dies back to the ground at the end of the growing season. The term herbaceous means either having the characteristic of a herb or being leaf-like in color and texture. A related term is Forb, which means a non-woody plant that is not a grass and is not grass-like. This means that the term forb excludes sedges (Cyperaceae) and rushes (Juncaceae) along with grasses (Poaceae).