It is an institution that is in charge, among other functions, of guarantying the proper functioning of the financial system, bringing the currency into circulation, etc. Examples of central banks are the federal reserve bank in the U.S., the bank of England in the U.K. and the European Central Bank.

The central bank is legally independent from the country´s government.

• Owns and manages the currency reserves and precious metals - Promotes the good functioning and stability of the financial system
• Supervises the solvency and the compliance of the specific regulations of the entities that depend on it.
• Brings the currency into circulation
• Elaborates and publish the statistics related with its functions
• Offers services as treasury and financial agent of the public debt 
• Advises the government
• Issues the banknotes in legal tender

As for the European Central Bank, its functions are:

• Define and execute the euro monetary policy 
• Establish interest rates 
• Take care of the exchange transactions
• Own and manage the official currency reserves of the euro zone countries
• Promote the good functioning of the payment systems
• Authorize issuing of banknotes
• Perform different economic studies
• Cooperate in Europe, as well as internationally