salesperson vs sales rep

salesperson and sales rep both are nouns.

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

As nouns, salesperson and sales rep are synonyms defined as:

salesperson and 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 synonyms of salesperson include sales representative.

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