Can bank tellers see your balance?

Good day, I'm curious about a specific aspect of banking transactions. When I visit a bank teller to conduct a routine transaction, such as a withdrawal or deposit, do they have immediate access to view my account balance? Is this information displayed prominently on their screens, or do they need to specifically request it? Additionally, what measures are in place to ensure the confidentiality of my account information and to prevent unauthorized access by bank staff?