truth vs tautology

truth and tautology both are nouns.

Word	Noun	Adjective	Verb	Adverb
truth	Yes	No	No	No
tautology	Yes	No	No	No

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

Other hyponyms of truth include gospel, gospel truth, truism.

truth (noun)	tautology (noun)
the quality of being near to the true value	useless and pointless repetition
a fact that has been verified	(logic) a statement that is necessarily true
a true statement
conformity to reality or actuality