The peso is used as the currency in several countries, but most notably, it is the official currency of Mexico. The Mexican peso, symbolized as "$" or "MXN," is one of the oldest currencies still in use today, with origins dating back to the 16th century. In addition to Mexico, other countries like Argentina, the Philippines, and Cuba also utilize their own versions of the peso. The currency is subdivided into centavos and is known for its fluctuating exchange rates, influenced by economic factors such as inflation and trade balances.