My brother works as a Bank teller,seems to me as they work behind the counter
well a teller is an employee of a bank who deals directly with customers.
When did the usage come into existence?
well sometimes they are known as  this employee is known as a cashier or customer representative
That's good! So I believe we are discussion is banking. So when was the first ever banking system establish?
i think that was the 1933 banking act. but now all tellers need experince in handleing cash