Azeri is also called Azerbaijani and Torki. It is the principal language of Azerbaijan and is widely spoken in northwestern Iran. It is classified in the Oghuz branch of Turkic languages. It has received influences from both Arabic and Farsi. For centuries it has been considered a language of lyric poetry, but in recent times has become a common language in the región for science, engineering and journalism. It was originally written in a Perso-Arabic script, but was changed to Latin characters, and then to Cyrillic by the Soviets. Since independence, the Latin script is used. Estimates of the number of speakers varies, especially due to uncertainty about the figures from Iran. An estimated 20.1 million speak Azeri in Azerbaijan, many as a second language, with another 1.5 million in Iran.