No one knows for sure who first invented such money, but historians believe metal objects were first used as money as early as 5,000 B.C.
Around 700 B.C., the Lydians became the first Western culture to make coins. Other countries and civilizations soon began to mint their own coins with specific values. Using coins with set values made it easier to compare values and trade money for goods and services.
Before the invention of currency (and for many centuries after), bartering societies would trade goods for other goods.