The location of Bosnia and Herzegovina. Croatia borders the country on the north, west, and south, Serbia and Montenegro on the east and southeast, and the Adriatic Sea on the southwest. The country's name comes from the two regions Bosnia and Herzegovina, which have a vaguely defined border between them. Bosnia occupies the northern areas which are roughly four fifths of the entire country, while Herzegovina occupies the south part of the country. The country consists of two political entities, the Federation of Bosnia and Herzegovina and Republika Srpska, with District Brčko as a de facto third entity.Formerly one of the six federal units constituting the Socialist Federal Republic of Yugoslavia, Bosnia and Herzegovina gained its independence during the Yugoslav wars of the 1990s.