Azerbaijan or Azarbaijan, also known as Iranian Azerbaijan, is a historical region in northwestern Iran that borders Iraq and Turkey to the west, and the Nakhchivan Autonomous Republic, Armenia, and the Republic of Azerbaijan proper to the north.

Azerbaijani or Azeri, also referred to as Azeri Turkic, is a Turkic language from the Oghuz sub-branch. It is spoken primarily by the Azerbaijani people, who live mainly in the Republic of Azerbaijan, where the North Azerbaijani variety is spoken, and in the Azerbaijan region of Iran, where the South Azerbaijani variety is spoken. North Azerbaijani has official status in the Republic of Azerbaijan and Dagestan, but South Azerbaijani does not have official status in Iran, where the majority of Azerbaijani people live. Azerbaijani is also spoken to lesser varying degrees in Azerbaijani communities of Georgia and Turkey and by diaspora communities, primarily in Europe and North America.