Persian, also known by its endonym Farsi, is a Western Iranian language belonging to the Iranian branch of the Indo-Iranian subdivision of the Indo-European languages. Persian is a pluricentric language predominantly spoken and used officially within Iran, Afghanistan, and Tajikistan in three mutually intelligible standard varieties, namely Iranian Persian (officially known as Persian), Dari Persian (officially known as Dari since 1964) and Tajiki Persian (officially known as Tajik since 1999). It is also spoken natively in the Tajik variety by a significant population within Uzbekistan, as well as within other regions with a Persianate history in the cultural sphere of Greater Iran. It is written officially within Iran and Afghanistan in the Persian alphabet, a derivation of the Arabic script, and within Tajikistan in the Tajik alphabet, a derivation of the Cyrillic script.
Modern Persian is a continuation of Middle Persian, an official language of the Sasanian Empire (224–651 CE), itself a continuation of Old Persian, which was used in the Achaemenid Empire (550–330 BCE). It originated in the region of Pars (Persia) in southwestern Iran. Its grammar is similar to that of many European languages.