In simple terms, monetary policy describes the tools used by a central bank to control the supply of money in the economy. This increases or decreases the flow of money and thus increases or decreases economic activity.
On the other hand, Fiscal policy describes how a government's chief executive and congress pass laws to 1) raise money (mainly through various taxes) and 2) spend money. Fiscal policy involves making decisions about what the government believes should be their spending priorities, such as national defense, public safety, public health, public education, scientific research, public welfare, social security, pensions, and so on.
Mandel Chapter 11 (it's in ADI-Contents-Mandel Chapters) goes into great detail, but this graphic captures several key points.
National debt as a percentage of GDP
A key question for politicians and government officials to make on Fiscal Policy is: Should we borrow money to pay for programs if we don't generate enough from taxes. The risk of borrowing is that you accumulate more debt than you can pay back. Many governments have been adding debt rapidly.
Supposedly, the debt of a well managed government should not need exceed 60% of GDP (this metric is part of Exercise 4). But look at the recent national debt figures. As you can see in the chart below, the euro zone average in December 2019, before the effects of the corona virus, was 84.1%. The U.S. was at 107% and Spain was at 95.5%. Those percentages are now much higher for all countries as they borrow and spend to reverse the financial crisis. We will talk more about this on Friday.