The way the currency of a country is issued, managed and regulated called the monetary system of the country. Monetary standards may be of different kinds.
If one metal is the ultimate measure of value in the country standard will be metallic. If one metal is the standard that monometallism. If that metal is gold it will be called gold standard similarly if that is silver it will be called silver standard.
When two metals are standard metals, monetary standard will be called bimetallism. Under this system a ratio is fixed by law between the values of these two metals.
3. Paper Standard:
Where the money of the country is not convertible directly or indirectly into any metal, it will be called paper standard. Monetary Standards
4. Exchange Standard:
If any country keeps the value of standard coins fixed in terms of some foreign money for purposes of foreign trade, the monetary standard is called exchange standard.