Money is a legal medium of exchange or standard of measurement of value, issued by the government of a country in the form of paper, gold, silver, or other metal printed with certain shapes and images. Then in 1100 BEFORE CHRIST, the Chinese people minted coins using gold and bronze. The round coin is given a hole in the middle. This hole is used to arrange coins into a series so that they are easier to carry everywhere. In 2008, an anonymous entity calling himself Satoshi Nakamoto introduced the Bitcoin system to the world.