Origin
The traditional distinction is between two different approaches to economics: Keynesian economics, focusing on demand; and supply-side (or neo-classical) economics, focusing on supply. Neither view is typically endorsed to the complete exclusion of the other, but most schools do tend clearly to emphasize one or the other as a theoretical foundation.

Keynesian economics focuses on aggregate demand to explain levels of unemployment and the business cycle. That is, business cycle fluctuations should be reduced through fiscal policy (the government spends more or less depending on the situation) and monetary policy. Early Keynesian macroeconomics was "activist," calling for regular use of policy to stabilize the capitalist economy, while some Keynesians called for the use of incomes policies.
Supply-side economics delineates quite clearly the roles of monetary policy and fiscal policy. The focus for monetary policy should be purely on the price of money as determined by the supply of money and the demand for money. It advocates a monetary policy that directly targets the value of money and does not target interest rates at all. Typically the value of money is measured by reference to gold or some other reference. The focus of fiscal policy is to raise revenue for worthy government investments with a clear recognition of the impact that taxation has on domestic trade. It places heavy emphasis on Say's law, which states that recessions do not occur because of failure in demand or lack of money. Schools
In order to try to avoid major economic shocks, such as great depression, governments make adjustments through policy changes which they hope will succeed in stabilizing the economy. Governments believe that the success of these adjustments is necessary to maintain stability and continue growth. This economic management is achieved through two types of strategies.

Fiscal Policy
Monetary Policy