A voivodeship is the area administered by a voivode (Governor) in several countries of central and eastern Europe. Voivodeships have existed since medieval times in Poland, Wallachia, Hungary, Lithuania, Latvia, Ukraine, Russia and Serbia. The administrative level of area (territory) of voivodeship resembles that of a duchy in western medieval states, much as the title of voivode was equivalent to that of a duke. Other roughly equivalent titles and areas in medieval Eastern Europe included ban (bojan, vojin or bayan) and banate.
In a modern context, the word normally refers to one of the provinces (województwa) of Poland. Poland as of 2015 has 16 województwa.
More information on the Wikipedia page .