Currency is a medium of exchange, comes in various forms, and allows for swift transaction and trade. Companies sell goods and services, and most generally believe that currency has value, which is why they exchange items for it. It replaced the barter system and created a more efficient, globalized financial system and economy. It also has problems, as governments print money across all currencies without backing the numerical value by assets. Currency enables day-to-day necessities, but without currency, our world would not function as it does.