What is the history of money?

Initially, societies used barter, exchanging goods and services directly. This was inefficient due to the "double coincidence of wants" problem. To overcome this, commodities like shells, salt, or precious metals (like gold and silver) became widely accepted as commodity money.

Later, representative money emerged, such as paper notes that could be exchanged for a fixed amount of a precious metal. Finally, fiat money, like the currency we use today, was introduced. Fiat money has value because a government declares it legal tender, not because it's backed by a physical commodity.