Hindu scripture is not limited to a single book in the same way as other world faiths; however, the four Vedas may be considered the main, or at least the original and most authoritative "holy books." Otherwise, the Hindu faith is informed by a series of texts, each categorized as either "Shruti" (Revelation, that which is heard) or "Smriti" (Human Composition or Tradition, that which is remembered).
The four Vedas (namely the Rig Veda, Yajur Veda, Sama Veda and Atharva Veda) fall into the Shruti category. These were compiled around 3500 BCE. The Upanishads, which are essentially commentaries of the highly esoteric Vedas, are also Shruti texts.
Smriti literature includes the Itihasas, which are comparable with the Greek Iliad and Odyssey as great epics, the Puranas, Sutras, sectarian Agamas, Vedangas, Dharmasastras and Darsana.