Human transactions have come far since the Stone Age. The commodity trading of our ancestors eventually gave way to money, which in the past few thousand years has cycled through different forms, from wampum beads and metal to paper. In the 21st century, it often manifests as intangible electronic transfers and even cryptocurrencies.
Money is one of humanity’s most momentous inventions. For millennia, it's made the world go round, and that’s no new sentiment: As the Latin writer Publilius Syrus put it in the first century B.C., “Money alone sets all the world in motion.” But what is this shape-shifting source of prosperity, anyway? For Americans, the word calls to mind pennies, nickels, dimes, quarters and dollars. Of course, these constitute the currency of just one nation, at one moment in time. The United Nations recognizes another 179 current world currencies, and hundreds or thousands more have long since gone the way of the shilling.
Besides, money is far more complex than the bills and coins we carry in our purses and wallets. Formal definitions typically note that it serves many purposes: a convenient unit of exchange, a way to store wealth long-term and a standardized measurement of value. This list only scratches the surface of money's uses.
