Farsi or Persian I opt for Farsi than Persian for the dominant language, used in the present Iran and the colonies abroad. Iran is a nation of multi-language cultures: Fars, Khuzi, Baluch, Turkman, Kurd, Armani, Asuri, Yahudi, Gilaani, Azari, Lor, and others. The Iranian nationalities have their own historically/ independently evolved languages. Some of them are remnants of the natives prior to the arrival of Aryans, 3000 years ago. Then, Farsi has its various dialects: Khoraasaani, Esfaahaani, Yazdi, Qazvini, Shiraazi, Tehraani, and others. Again, Tehraani has its own sub-dialects: Hasan-aabaadi, Chaale-meydaani, Shahre-Reyi (Raazi), Shemruni, etc. Moreover, Farsi is the name used by the Iranian government. It is the language of education, embassies, mass media and literature. All literature in Iran and Iranian colonies abroad, are labeled under Farsi. Therefore, Farsi is more descriptive of the the main language used in the Iranian plateau. Also, Western literature updates nowadays their historical vocabulary of other nations using the current prevailant terms. The legacy of some of the terms used in the West- mostly originated by adventurists, travelers, or lone linguists- is loosing ground. The term Persian is an abstraction. Historically it was used by Greeks, for a country faraway, over there. In Iran, it was an Arian tribe who went further south to Shiraaz in the plateau, arriving there later than their cousins, Medes in the north, 900 years Before Christ. At the time, there were natives, non-Arian, living in the plateau: Ilaamis, Lors, Gilaanis, Baluchis, and others. So Persian is a component and not an embodiment in the spectrum of languages used in the plateau. Whereas Farsi is one of the languages used here. Incidentally, Afghanistan is a multi-language country with secondary dialects. A person from Herat has hard time conversing with one from Kandahar or Kabul: Urdu, Dari, Pushtu, etc.