Bačka (Serbian Cyrillic: Бачка, pronounced [bâːtʃkaː]) or Bácska (pronounced [ˈbaːtʃkɒ]) is a geographical and historical area within the Pannonian Plain bordered by the river Danube to the west and south, and by the river Tisza to the east. It is divided between Serbia and Hungary. Most of the area is located within the Vojvodina region in Serbia and Novi Sad, the capital of Vojvodina, lies on the border between Bačka and Syrmia. The smaller northern part of the geographical area is located within Bács-Kiskun County in Hungary. Name.
https://en.wikipedia.org/wiki/Ba%C4%8Dka