Does it mean serving customers and working over tills?
And if you don't mind could you also add some details if it includes anything else (:
Much appreciated.
YES. The name just means serving customers. They will give you training in the job so don't worry about it. Good luck
It means serving customers. That could be on a till, or it could be anything else where you regularly have to talk to people and help them. If a company has a phone number to call with problems, the people who answer are in customer service. If a shop has a help desk, that's customer service. It can be so many things.
So if your sister advised you to put down "customer Service", why on earth did you not ask her to explain it? It simply means how you serve a customer.
Customer service is a dept that helps customers resolve problems. Till operation is checkout work.