A more thorough explanation:

CAMBIATOR

A cambiator is a historical term for an exchanger, usually of money. They were known as cambiatores monetae.

During the Middle Ages, travelers often needed to exchange their currency for the local currency of the country they were visiting. Cambiatori were individuals who provided this service. They would exchange one currency for another, taking a small fee for their services.

Another example of a cambiator is a money changer in a bank or currency exchange. They exchange one currency for another, based on the current exchange rate, and charge a fee for their services.

The examples illustrate how a cambiator would exchange one currency for another, taking a fee for their services. This was a common practice during the Middle Ages and is still used today in banks and currency exchanges.