First, the Fed cut its target for short term rates to just above zero and pledged to keep its target for short-term rates low "for some time."
This should give banks assurance that they will have access to cheap funds, economists said. This could help spur bank lending.
"Bank confidence in its ability to finance itself today and in the future is an essential for making loans," noted Stephen Gallagher, chief economist at Societe Generale.

More.. Fed promises explained in plain English - MarketWatch