Vedic Sanskrit

Vedic Sanskrit is an Old Indo-Aryan language. It is an archaic form of Sanskrit, an early descendant of Proto-Indo-Iranian. It is closely related to Avestan, the oldest preserved Iranian language. Vedic Sanskrit is the oldest attested language of the Indo-Iranian branch of the Indo-European family.

Vedic Sanskrit is the language of the Vedas, texts compiled over the period of early-to-mid 2nd to mid 1st millennium BC. Vedic Sanskrit has been orally preserved as a part of the Śrauta tradition of Vedic chanting, predating the advent of alphabetic writing in India by several centuries. For lack of both epigraphic evidence and an unbroken manuscript tradition, Vedic Sanskrit can be considered a reconstructed language. Especially the oldest stage of the language, Rigvedic Sanskrit, the language of the hymns of the Rigveda, is preserved only in a redacted form several centuries younger than the texts' composition. Recovering its original form is a matter of linguistic reconstruction.

From about the 6th century BC, in the classical period of Iron Age Ancient India, Vedic Sanskrit gave way to Classical Sanskrit as defined by the grammar of Pāṇini.

Read more about Vedic Sanskrit:  Phonology, Principal Differences From Classical Sanskrit, Grammar