World currencies have a rich and complex history, reflecting human economic and cultural development. Over time, the form, value and function of currency have changed significantly. From barter systems to digital currencies, each phase reflects changes in the way humans transact. The barter system, which became an early method of trade, is characterized by the direct exchange of goods without the use of money. However, this system has limitations, such as the need for a “double coincidence of wants,” which requires both parties to have goods that the other party wants. To overcome these limitations, the emergence of valuable goods—such as salt, spices, and precious metals—became the first step towards the use of currency. Around 3,000 BC, in Mesopotamia, the first known currency was coins made of metal. These coins were not only easy to carry, but also had recognized intrinsic value. Coins issued by kingdoms, including Lydia and Persia, became the basis of a more organized monetary system. In China, around 1,000 BC, payment methods began using paper money due to the need for easier transactions. These notes were originally used by merchants, and were gradually adopted by the government to reduce the weight of carrying metal. This concept continued and influenced global trade for centuries. In the 17th century, Europe witnessed a financial revolution when banks began to issue notes or debt securities that could be exchanged for gold. The bimetallism system, namely the use of gold and silver as the basis of currency, became dominant until the end of the 19th century. Countries began to set fixed exchange rates for economic stability. Entering the 20th century, many countries began to adopt a fiat-based monetary system, where the value of currency is determined by people’s trust in the government that issues it, not by physical commodities. World Wars I and II accelerated this transition, resulting in many countries abandoning the gold standard. From 1971, the Bretton Woods system regulating the exchange rate between the US dollar and gold ended, and currencies began to move within a system of flexible exchange rates. Technological advances, especially in electronic payments, are changing the way people transact. Nowadays, cryptocurrencies like Bitcoin are starting to gain popularity, shaking up the existing currency traditions. To date, currencies continue to develop with technological innovation and changes in global economic policies. The process of globalization also encourages integration and interdependence among various currencies, making international trade increasingly complex. Currency supervision and regulation by international financial institutions such as the IMF and World Bank is increasingly important to maintain global economic stability. With these various changes, it is important for economic actors and society to understand the history and development of world currencies. Understanding how currencies function and their development will help individuals and companies plan better financial and investment strategies in the future.