UK interest rates are currently at 0.5% - the lowest level in the Bank of England's 315-year history.
The dramatic series of cuts in the Bank rate over the past few months has been aimed at easing the credit crunch and getting the banks to lend again.
But that has not happened, at least not to the extent that the Bank thinks is necessary to revive consumer spending and economic growth.
So the Bank is now expanding the amount of money in the system by £75bn - a process known as "quantitative easing".