I've always considered "herbs" to be more temperate climate plants, parts of which have medicinal uses (the active part may be leaf, root, flower, bark, seed, or different parts may have different medicinal uses). "Spices" tend to be more exotic, coming from the tropics, and difficult to find locally in their fresh form -- or, they are seasoning plants which DON'T have specific medicinal uses (e.g. oregano, basil), usually in their dried forms.
I've been taught that dried seasonings go in the beginning of cooking so their flavor can develop, but to leave fresh seasonings to the last 15 minutes so the heat doesn't destroy their flavor.
I've always considered "herbs" to be more temperate climate plants, parts of which have medicinal uses (the active part may be leaf, root, flower, bark, seed, or different parts may have different medicinal uses). "Spices" tend to be more exotic, coming from the tropics, and difficult to find locally in their fresh form -- or, they are seasoning plants which DON'T have specific medicinal uses (e.g. oregano, basil), usually in their dried forms.
I've been taught that dried seasonings go in the beginning of cooking so their flavor can develop, but to leave fresh seasonings to the last 15 minutes so the heat doesn't destroy their flavor.