Quantitative easing (QE) is a monetary policy used by central banks to stimulate the economy when standard monetary policy has become ineffective.

QE is aimed at stimulating economic activity, such as increasing consumer spending

One of the main tools they have to control growth is raising or lowering interest rates. Lower interest rates encourage people or companies to spend money, rather than save.
But when interest rates are almost at zero, central banks need to adopt different tactics – such as pumping money directly into the financial system.
This process is known as quantitative easing or QE.