salesgirl vs salesperson

salesgirl and salesperson both are nouns.

Word	Noun	Adjective	Verb	Adverb
salesgirl	Yes	No	No	No
salesperson	Yes	No	No	No

As nouns, salesperson is a hypernym of salesgirl; that is, salesperson is a word with a broader meaning than salesgirl:

salesgirl: a woman salesperson
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)

Other hypernyms of salesgirl include sales rep, sales representative, adult female, woman.

salesgirl (noun)	salesperson (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)