offspring vs baby

offspring and baby both are nouns.

Word	Noun	Adjective	Verb	Adverb
offspring	Yes	No	No	No
baby	Yes	No	Yes	No

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

offspring (noun)	baby (noun)
any immature animal	a project of personal concern to someone
something that comes into existence as a result	a very young mammal
the immediate descendants of a person	a very young child (birth to 1 year) who has not yet begun to walk or talk
	the youngest member of a group (not necessarily young)
	an immature childish person
	an unborn child; a human fetus
	a beloved person; used as terms of endearment

offspring (verb)	baby (verb)
	treat with excessive indulgence