(i) Currency is the medium of exchange in a country.
(ii) The Indian currency is called the Indian Rupee.
(iii) In a country the foreign currency is called foreign exchange.
(iv) Purchasing capacity of all currencies in the world are compared using the US dollar as the standard currency.
(v) This value differs from country to country.
(vi) Most of the international trade transactions are carried out in US dollar.

(i) The metals such as silver and gold gained importance gradually all over the world.
(ii) So, these metals were used as standard value in the exchange of goods.
(iii) This was called as natural money

The metals such as silver, gold and copper were used first. They were called ancient currency.

Money supply is divided into four.
M₁ = Currency held with the public + cash Reserves in commercial and Co-operative banks + cash reserves in the RBI.
M₂ = M₁ + Money saved in Post office and bank savings Accounts
M₃ = M₁+ Time Deposits in Commercial and co-operative banks
M₄ = M₃ + Post office savings Money

(i) A government has the responsibility to regulate money supply and oversee the monetary policy.
(ii) Hoarding of money must be avoided at all costs in a country's economy.
(iii) Only then money can be saved in banks.
(iv) Dr. B.R. Ambedkar's Ph.D. thesis on 'The Problem of the Rupee - Its origin and solution' was the reference tool and provided guidelines for the Reserve Bank of India Act of 1934.
(v) All the major and important banks were nationalised (1969) in India.
(vi) The Reserve Bank of India (RBI) regulates the circulation of currency in India.
(vii) The Reserve Bank of India started its operations on 1st April 1935.
(viii) It was permanently moved to Mumbai from the year 1937.
(ix) RBI was nationalised in 1949. 85% of the printed currency is let for circulation. According to the statistics available as on August 2018, currency worth of 19 lakh crore are in circulation.