From 1870 to 1914, mosst currencies were in terms of gold. Gold was used as the common denominator for all currencies, which meant that all currencies pegged at a fixed rate to gold. There were a few different kinds of gold standards, such as Gold specie, Gold exchange, and the Gold bullion standards.
GOLD SPECIE STANDARD- monetary unit associated with circulating gold coins.
GOLD EXCHANGE STANDARD- circulation of coins only made of silver.
GOLD BULLION STANDARD- gold coins do not circulate, however, gold bullion sold at a fixed price.
Since many of the banks had a huge inflow of gold, the central banks created gold reserves.
In 1934, the Gold Reserve Act made it illegal for people to have ownership of gold, unless it was in the form of jewelry.( President Roosevelt) Circulation of gold coins were no longer available and the federal reserve and illuminati had full control of everything gold.
What we use today?
Today almost every country uses fiat money. Fiat money is intrinsically useless only for a use of medium exchange. The value of money today is set by the supply and demand from the economy. (goods or services)