banker vs teller

banker and teller both are nouns.

Word	Noun	Adjective	Verb	Adverb
banker	Yes	No	No	No
teller	Yes	No	No	No

As nouns, teller is a hyponym of banker; that is, teller is a word with a more specific, narrower meaning than banker:

Other hyponyms of banker include bank clerk, cashier.

banker (noun)	teller (noun)
a financier who owns or is an executive in a bank	an employee of a bank who receives and pays out money
the person in charge of the bank in a gambling game	an official appointed to count the votes (especially in legislative assembly)
	someone who tells a story