newsletter vs news report

newsletter and news report both are nouns.

Word	Noun	Adjective	Verb	Adverb
newsletter	Yes	No	No	No
news report	Yes	No	No	No

As nouns, news report is a hypernym of newsletter; that is, news report is a word with a broader meaning than newsletter:

newsletter: report or open letter giving informal or confidential news of interest to a special group
news report: a short account of the news

Other hypernyms of newsletter include account, report, story, write up.

newsletter (noun)	news report (noun)
report or open letter giving informal or confidential news of interest to a special group	a short account of the news