herbal therapy vs therapy

herbal therapy and therapy both are nouns.

Word	Noun	Adjective	Verb	Adverb
herbal therapy	Yes	No	No	No
therapy	Yes	No	No	No

As nouns, therapy is a hypernym of herbal therapy; that is, therapy is a word with a broader meaning than herbal therapy:

herbal therapy: the use of plants or plant extracts for medicinal purposes (especially plants that are not part of the normal diet)
therapy: (medicine) the act of caring for someone (as by medication or remedial training etc.)

Other hypernyms of herbal therapy include treatment.

herbal therapy (noun)	therapy (noun)
the use of plants or plant extracts for medicinal purposes (especially plants that are not part of the normal diet)	(medicine) the act of caring for someone (as by medication or remedial training etc.)