herb vs tea

herb and tea both are nouns.

Word	Noun	Adjective	Verb	Adverb
herb	Yes	No	No	No
tea	Yes	No	No	No

As nouns, tea is a hyponym of herb; that is, tea is a word with a more specific, narrower meaning than herb:

herb (noun)	tea (noun)
aromatic potherb used in cookery for its savory qualities	a beverage made by steeping tea leaves in water
a plant lacking a permanent woody stem; many are flowering garden plants or potherbs; some having medicinal properties; some are pests	a light midafternoon meal of tea and sandwiches or cakes
	dried leaves of the tea shrub; used to make tea
	a tropical evergreen shrub or small tree extensively cultivated in e.g. China and Japan and India; source of tea leaves