"The city of Berlin is one of three city-states and one of the 16 states of Germany. It has its own House of Representatives (Abgeordnetenhaus) which acts as the state parliament. The Senate of Berlin is the executive of the city, comprising 8 senators and a Governing Mayor. The city is divided into twelve borough's, each of which maintains its own borough council and mayor, though they all remain subordinate to the Senate of Berlin. Also, through a practice known as ""sister cities"" Berlin partners with 17 cities across the world in order to foster economic and cultural relations, making Berlin a truly global city."