finalization vs completion

finalization and completion both are nouns.

Word	Noun	Adjective	Verb	Adverb
finalization	Yes	No	No	No
completion	Yes	No	No	No

As nouns, completion is a hypernym of finalization; that is, completion is a word with a broader meaning than finalization:

Other hypernyms of finalization include closing, culmination, mop up, windup.

finalization (noun)	completion (noun)
the act of finalizing	a concluding action
	(American football) a successful forward pass in football