saleswoman vs sales rep

saleswoman and sales rep both are nouns.

Word	Noun	Adjective	Verb	Adverb
saleswoman	Yes	No	No	No
sales rep	Yes	No	No	No

As nouns, sales rep is a hypernym of saleswoman; that is, sales rep is a word with a broader meaning than saleswoman:

saleswoman: a woman salesperson
sales rep: a person employed to represent a business and to sell its merchandise (as to customers in a store or to customers who are visited)

Other hypernyms of saleswoman include sales representative, salesperson, adult female, woman.

saleswoman (noun)	sales rep (noun)
a woman salesperson	a person employed to represent a business and to sell its merchandise (as to customers in a store or to customers who are visited)