They’re essentially printing more money in hopes of people spending more money
This relates to the quantity theory of money, which shows that nominal growth can be increased in the short-term by printing additional money (i.e. increasing the supply of money). What this means is that printing money increases the flow of money around the economy and stimulates economic growth. In the long-run prices will rise (inflation) to adjust to the new level of money (i.e. it is only a short-term fix).
Quantitative easing is a number given to stabilize the money supply, interest rates to control inflation and allow moneys for lending for growth in production of products or services.
It is a government monetary policy occasionally used to increase the money supply by buying government securities or other securities from the market. Quantitative easing increases the money supply by flooding financial institutions with capital in an effort to promote increased lending and hence liquidity.
When the liquidity in an Economy increases it leads to increased buying power of the people and thus increases the demand in the economy which in turn leads to production which improves the GDP of the Economy.
Central banks tend to use quantitative easing when interest rates have already been lowered to near 0% levels and have failed to produce the desired effect.
The major risk of quantitative easing is that although more money is floating around, there is still a fixed amount of goods for sale. This will eventually lead to higher prices or inflation.
Quantitative analysis a tools for managerial efficiency