juvenile vs child

juvenile and child both are nouns.

Word	Noun	Adjective	Verb	Adverb
juvenile	Yes	Yes	No	No
child	Yes	No	No	No

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

juvenile (noun)	child (noun)
a young person, not fully developed	a young person of either sex
	a human offspring (son or daughter) of any age
	an immature childish person
	a member of a clan or tribe

juvenile (adjective)	child (adjective)
of or relating to or characteristic of or appropriate for children or young people
displaying or suggesting a lack of maturity