commentator vs reviewer

commentator and reviewer both are nouns.

Word	Noun	Adjective	Verb	Adverb
commentator	Yes	No	No	No
reviewer	Yes	No	No	No

As nouns, commentator and reviewer are synonyms defined as:

commentator and reviewer: a writer who reports and analyzes events of the day

commentator (noun)	reviewer (noun)
a writer who reports and analyzes events of the day	a writer who reports and analyzes events of the day
an expert who observes and comments on something	someone who reads manuscripts and judges their suitability for publication