Dari derives from Fârsi-e Darbâri which means Persian of the (royal) courts. It developed at the royal courts of the Samanids (980 AD) in Central Asia and became the major language of the region. Today, it is the local name used for the Persian language in official documents of Afghanistan. It is also the name of the Persian language in classical Persian poetry.

Persian is the major language of Afghanistan and it is spoken in the northern and western parts of the country including the capital Kabul in the east. Approximately 60% of the population of Afghanistan (Tajik, Uzbek, Turkmen, Hazara, some Pashtoon), speaks Persian, with bilingualism widespread. It is the primary language of the Tajik, Hazara, and Chahar Aimak peoples. The language serves as the means of communication between speakers of different languages in Afghanistan.

The syntax of Afghanistan's Persian does not differ greatly from Iran's Persian (locally called Farsi), but the stress accent is less prominent in Afghanistan's Persian than in Iran's Persian. To mark attribution, spoken Afghan Persian uses the suffix -ra. The vowel system also differs from that of Iranian Persian, to some degree.

Some people don't consider Dari itself to be a dialect or a language. They consider it to be the written language (written Persian, with no dialects), while they consider Farsi the spoken language (spoken Persian, which has many different dialects). It is also believed by some, that Dari should not be called Afghan Persian, because it has existed centuries before the creation of Afghanistan and also that the term is used by certain Iranians to refer to the language, including Mahmoud Dowlatabadi . In this case, Dari can be considered a synonym for Persian language.