From Traderpedia

The European Central Bank (ECB) is the central bank of the so-called eurozone. It is responsible for monetary policy in regards to the group of nations whose currency is the Euro.

[edit] Objective of the ECB

The primary mandate of the ECB is to maintain price stability. This means keeping inflation in check at no more than 2% across the eurozone.

[edit] Tools of the ECB

The primary tool in the hands of the ECB is interest rates. Through the change of these rates, the ECB is able to influence economic factors and markets.