John 2:15 - "And making a rope of cords, he drove them all, with the sheep and oxen, out of the temple; and he poured out the coins of the money-changers and overturned their tables."
In biblical times, the money-changer was a familiar sight. He would sit at a table in a conspicuous place to change the people’s money from one kind to another. Interest, which was often excessive and unfair, was charged for this transaction. He also changed large coins into smaller amounts.
These men were particularly at work in the Temple area, since the people could not use Roman coins to buy sacrificial birds and animals. Because the coins held a picture of Caesar, which to the Jew, was a graven image, he had to exchange them for Temple shekels, Jesus’ act was probably a protest against the excessive charge (31 cents) for this service, rather than the money-changers as a class.
Today about the only comparable occupation we have is that of the person who exchanges the currency of one country for that of another. Of course, since he is giving a service, he is entitled to a fee, and he charges one, but this is regulated by law and cannot be exceeded without dire consequences for him.