Persian Language, also known as Farsi, is the most widely spoken member of the Iranian branch of the Indo-Iranian languages, a subfamily of the Indo-European languages. It is the language of Iran (formerly Persia) and is also widely spoken in Afghanistan and, in an archaic form, in Tajikistan and the Pamir Mountain region.

Persian is spoken today primarily in Iran, Afghanistan, but was historically a more widely understood language in an area ranging from the Middle East to India. Significant populations of speakers in other Persian Gulf countries (Bahrain, Iraq, Oman, People's Democratic Republic of Yemen, and the United Arab Emirates), as well as large communities in the USA.

Total numbers of speakers is high: over 30 million Farsi speakers (about 50% of Iran's population); over 7 million Dari Persian speakers in Afghanistan (25% of the population); and about 2 million Dari Persian speakers in Pakistan.

Three phases may be distinguished in the development of Iranian languages: Old, Middle, and Modern. Old Iranian is represented by Avestan and Old Persian. Avestan, probably spoken in the northeast of ancient Persia, is the language of the Avesta, the sacred scriptures of Zoroastrianism. Except for this scriptural use, Avestan died out centuries before the advent of Islam. Old Persian is recorded in the southwest in cuneiform inscriptions of the Persian kings of the Achaemenid dynasty (circa 550-330 BC), notably Darius I and Xerxes I. Old Persian and Avestan have close affinity with Sanskrit, and, like Sanskrit, Greek, and Latin, are highly inflected languages.

Farsi is a member of the Iranian branch of the Indo-Iranian language family;
it is the official language of Iran. It is most closely related to Middle and
Old Persian, former languages of the region of Fars ("Persia") in southwestern
Iran. Modern Persian is thus called Farsi by native speakers. Written in
Arabic characters, modern Persian also has many Arabic loanwords and an
extensive literature.

Persian, Not Farsi