These are all terms that refer to the Nederlandsche Bank’s three key tasks: contributing to and implementing the monetary policy, exercising prudential supervision and promoting the smooth operation of payment systems. By ensuring an adequate performance of these tasks, the Nederlandsche Bank controls the stability of the Dutch financial system. Financial stability in turn is difficult to achieve without properly functioning central banks.
If we had a blazon, which we don’t, it would probably read "Guardian of financial stability".