Avestan is an ancient language that was used in the sacred texts of Zoroastrianism, known as the Avesta. It is part of the Iranian branch of the Indo-Iranian languages and is closely related to Sanskrit. Avestan was primarily used for religious purposes and is characterized by its complex grammar and unique script. The language has two main dialects: Old Avestan and Younger Avestan. Old Avestan is found in the oldest portions of the Avesta, while Younger Avestan appears in later texts. Avestan is significant for understanding the history and beliefs of ancient Persia and the development of Zoroastrianism.