People around the world used many different things for currency, but eventually metal coins became the most popular form of money in most of Europe and Asia.

People used gold, silver and copper as money because it was pretty, and useful, and hard to get. The first metal money was in lumps and bars, and how much it was worth depended on how much it weighed. This wasn't very convenient, because if someone only wanted to spend part of their money, they had to melt down the metal to divide it up.

Eventually, people figured out that they could make metal into pieces of equal size and weight. They stamped the weight on the piece of metal, along with some design that proved it was real, like a picture of the king. These were the first coins.

The problem with using metal as money is that it's very heavy, and hard to carry around. People needed an easier way to make big payments, so they invented paper money.