Arran (Middle Persian form), also known as Aran, Ardhan (in Parthian), Al-Ran (in Arabic),Aghvank and Alvank (in Armenian), (Georgian: რანი-Ran-i ) or Caucasian Albania (in Latin), was a geographical name used in ancient and medieval times to signify the territory which lies within the triangle of land, lowland in the east and mountainous in the west, formed by the junction of Kura and Aras rivers, including the highland and lowland Karabakh,Mil plain and parts of the Mughan plain, and in the pre-Islamic times, corresponded roughly to the territory of modern-day Republic of Azerbaijan. The term is the Middle Persian equivalent to the Greco-Roman Albania. It was known as Aghvania, Alvan-k in Armenian, and Al-ran (Arabized form of Arran) in Arabic.
Today, the term Aran is mainly used in Azerbaijan to indicate territories consisting of Mil and Mughan plains (mostly, Beylaqan, Imishli, Saatli, Sabirabad provinces of the Republic of Azerbaijan). It has also been used by Iranian historian Enayatollah Reza to refer to the country of Azerbaijan, freeing the name "Azerbaijan" to refer to a region within Iran. (The bulk of the territory of Rep. of Azerbaijan was the historic Shirvan as well as Kuba/Qubbah).