An oblast is a type of administrative division of Belarus, Bulgaria, Kazakhstan, Kyrgyzstan, Russia, Ukraine, and the former Soviet Union and Kingdom of Serbs, Croats and Slovenes.
Official terms in successor states of the Soviet Union differ, but some still use a cognate of the Russian term, e.g. voblast (voblasts, voblasts', [ˈvobɫasʲtsʲ]) is used for regions of Belarus, and oblys (plural: oblystar) for regions of Kazakhstan.
The word "oblast" is a loanword in English, but it is, nevertheless, often translated as "area", "zone", "province", or "region". The last translation may lead to confusion, because "raion" may be used for other kinds of administrative subdivision, which may be translated as "region" or "district", depending on the context.
Since 1997, Bulgaria has been divided into 28 oblasts, usually translated as "provinces". Before, the country was divided into just nine units, also called oblast.
In the Russian Empire, oblasts were considered to be administrative units and were included as parts of Governorates General or krais. The majority of then-existing oblasts were on the periphery of the country (e.g. Kars Oblast or Transcaspian Oblast) or covered the areas where Cossacks lived.