Codiaeum variegatum vs shrub

Codiaeum variegatum and shrub both are nouns.

Word	Noun	Adjective	Verb	Adverb
Codiaeum variegatum	Yes	No	No	No
shrub	Yes	No	No	No

As nouns, shrub is a hypernym of Codiaeum variegatum; that is, shrub is a word with a broader meaning than Codiaeum variegatum:

Codiaeum variegatum: grown in many varieties for their brightly colored foliage; widely cultivated as a houseplant
shrub: a low woody perennial plant usually having several major stems

Other hypernyms of Codiaeum variegatum include bush.

Codiaeum variegatum (noun)	shrub (noun)
grown in many varieties for their brightly colored foliage; widely cultivated as a houseplant	a low woody perennial plant usually having several major stems