Politics of Italy is conducted through a Parliamentary Republic with a multi-party system. Italy has been a democratic republic since 2 June 1946, when the monarchy was abolished by popular referendum and a constituent assembly was elected to draft a constitution, which was promulgated on 1 January 1948.

The executive power is exercised collectively by the Council of Ministers, which is led by the Prime Minister, officially referred to as President of the Council ("Presidente del Consiglio"). Legislative power is vested in the two houses of parliament primarily, and secondarily on the Council of Ministers, which can introduce bills and holds the majority in the parliament. The judiciary is independent of the executive and the legislative branches. It is headed by the High Council of the Judiciary. The president is the head of state, though his position is separate from all branches. 

Source: Wikipedia