What Is Herb?
In general use, herbs are plants with savory or aromatic properties that are used for flavoring food, in medicine, or as fragrances. Culinary use typically distinguishes herbs from spices. Herbs refer to the leafy green or floweringparts of a plant (either fresh or dried), while spices are usually dried and produced from other parts of the plant, including seeds, berries, bark, roots and fruits.

Source: https://en.m.wikipedia.org/wiki/Herb