European Central Bank - ECB
  
In general, central banks oversee an economy's currency and control things like interest rates. The U.S. has the Federal Reserve. The U.K. has the Bank of England. Fiji has the Reserve Bank of Fiji.
And the European Union has the European Central Bank.
Just as the Fed controls the flow of U.S. dollars, the ECB controls the euro. It also acts as a regulator for the EU, including setting interest rates. Its stated objective is to maintain price stability within the Eurozone, which basically means avoiding high inflation (and preventing deflation).
The ECB's main decision-making body is called the "Governing Council." It is headed by the President of the Bank (the approximate equivalent of the Chairman of the Federal Reserve). The president is part of the six-person Executive Board (all of whom also sit on the Governing Council). They are joined by governors of the National Central Banks, representing the countries within the Eurozone.