error vs erratum

error and erratum both are nouns.

Word	Noun	Adjective	Verb	Adverb
error	Yes	No	No	No
erratum	Yes	No	No	No

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

error: part of a statement that is not correct
erratum: a mistake in printed matter resulting from mechanical failures of some kind

Other hyponyms of error include corrigendum, literal, literal error, misprint, typo, typographical error.

error (noun)	erratum (noun)
a wrong action attributable to bad judgment or ignorance or inattention	a mistake in printed matter resulting from mechanical failures of some kind
(baseball) a failure of a defensive player to make an out when normal play would have sufficed
inadvertent incorrectness
departure from what is ethically acceptable
a misconception resulting from incorrect information
part of a statement that is not correct
(computer science) the occurrence of an incorrect result produced by a computer