sales outlet vs retail store

sales outlet and retail store both are nouns.

Word	Noun	Adjective	Verb	Adverb
sales outlet	Yes	No	No	No
retail store	Yes	No	No	No

As nouns, sales outlet and retail store are synonyms defined as:

Other synonyms of sales outlet include mercantile establishment, outlet.

sales outlet (noun)	retail store (noun)
a place of business for retailing goods	a place of business for retailing goods