What is monetarism in economics?

As the name suggests monetarism deals with regulations related to Money supply in the country. A school of thought in monetary economics which emphasizes the role of governments in controlling the amount of money in circulation (the money supply). Monetarists assert that variations in the money supply have major influences on national output in the short run and on price levels over longer periods, and that the objectives of monetary policy are best met by targeting the growth rate of the money supply rather than by engaging in discretionary policy.