Discount rate: It is the rate at which the Fed gives loans to
the banks and act as a lender of last resort in the market. if
there is inflation then this rate is increased and if the inflation
is low then this rate is lowered.
Reserver ratio, this is the ratio of the total deposit that the
banks have to keep with them, if the reserves are increased then
the money supply fall and if the reserve ratio is decreased then
the money supply is increased.
Open maket operation: Banks sells the government bonds to
maintain the money supply in the market.