The USD - US Dollar

The United States dollar (symbol: $; code: USD; often abbreviated as US$ or U.S. Dollar to differentiate it from other dollar-denominated currencies; also known as the dollar, U.S. dollar, American dollar, or informally buck) is the official coin of the United States and numerous other nations. The Coinage Act of 1792 established the United States dollar on par with the Spanish silver dollar, split it into 100 cents, and permitted the minting of coins with dollar and cent values. Federal Reserve Notes, which are commonly referred to as "greenbacks" due to their mostly green tint, are the type of U.S. banknotes that are issued.The Federal Reserve System, which serves as the country's central bank, manages the monetary policy of the United States.

A bimetallic standard of 371.25 grains of fine silver or, starting in 1837, 23.22 grains of fine gold, or $20.67 per troy ounce, was used to define the U.S. dollar at its inception. The dollar was exclusively tied to gold by the Gold Standard Act of 1900. Its conversion to gold was changed in 1934 to $35 per troy ounce. All ties to gold have been severed since 1971. 

After the First World War, the U.S. dollar emerged as a significant global reserve currency. The Bretton Woods Agreement, signed at the close of the Second World War, saw the dollar replace the pound sterling as the world's main reserve currency. The dollar, which is a free-floating currency, is the most often used currency in international trade.Additionally, it serves as both the de facto money and the official currency in a number of nationsusing Federal Reserve Notes (and, in certain instances, U.S. Coins) as legal tender.The amount of money in circulation as of February 10, 2021, was US$2.10 trillion, of which $2.05 trillion is in Federal Reserve Notes (the remaining $50 billion is in coins and older-style United States Notes).

Additionally, it serves as both the de facto money and the official currency in a number of nations.using Federal Reserve Notes (and, in certain instances, U.S. Coins) as legal tender.The amount of money in circulation as of February 10, 2021, was US$2.10 trillion, of which $2.05 trillion is in Federal Reserve Notes (the remaining $50 billion is in coins and older-style United States Notes).