The word "veda" translates from Sanskrit as knowledge or wisdom. They were composed and performed orally over a lengthy period of time, with the generally accepted dates being from around 1500 BCE to 1000 BCE, though some most probably originated before the Aryan migration into India. The Aryan poets who invented them handed them down orally for generations, and they are thought to have endured these transitions with little changes before they were written down. They are considered by Hindus to be revealed literature, having originated with the gods whose praise they sing. Important later Hindu scriptures such as the Brahmanas and the Upanishads are commentaries on the original Vedas.
The Vedas are the earliest texts which exist in Hinduism. There are four of them, and they are collectively referred to as Sruti, which means "that which is heard", and Samhita, which roughly means "collection." The oldest is called the Rig Veda, with the other three being the Yajur Veda, the Sama Veda, and the Atharva Veda. The Rig Veda is the most important, with the others having come later and are based upon it.