shop boy vs shop clerk

shop boy and shop clerk both are nouns.

Word	Noun	Adjective	Verb	Adverb
shop boy	Yes	No	No	No
shop clerk	Yes	No	No	No

As nouns, shop clerk is a hypernym of shop boy; that is, shop clerk is a word with a broader meaning than shop boy:

Other hypernyms of shop boy include boy, male child, clerk, salesclerk, shop assistant.

shop boy (noun)	shop clerk (noun)
a young male shop assistant	a salesperson in a store