The Avesta is an ancient collection of sacred texts from the Zoroastrian religion. It is composed of five books, known as the Yasna, Visperad, Vendidad, Yashts, and Khordeh Avesta. The Avesta is considered to be one of the most important scriptures in the Zoroastrian faith, and it is believed to have been written by the prophet Zarathustra. It contains prayers, hymns, and rituals that are still used in modern Zoroastrianism.