Proto-Indo-Aryan language in the context of "Proto-Indo-Iranian language"

Sanskrit literature is a broad term for all literature composed in Sanskrit. This includes texts composed in the earliest attested descendant of the Proto-Indo-Aryan language known as Vedic Sanskrit, texts in Classical Sanskrit as well as some mixed and non-standard forms of Sanskrit. Literature in the older language begins during the Vedic period with the composition of the Rigveda between about 1500 and 1000 BCE, followed by other Vedic works right up to the time of the grammarian Pāṇini around 6th or 4th century BCE (after which Classical Sanskrit texts gradually became the norm).

Vedic Sanskrit is the language of the extensive liturgical works of the Vedic religion, while Classical Sanskrit is the language of many of the prominent texts associated with the major Indian religions, especially Hinduism and the Hindu texts, but also Buddhism, and Jainism. Some Sanskrit Buddhist texts are also composed in a version of Sanskrit often called Buddhist Hybrid Sanskrit or Buddhistic Sanskrit, which contains many Middle Indic (prakritic) elements not found in other forms of Sanskrit.

Avestan (/əˈvɛstən/ ə-VESS-tən) is the liturgical language of Zoroastrianism. It belongs to the Iranian branch of the Indo-European language family and was originally spoken during the Avestan period (c. 1500 – 400 BCE) by the Iranians living in eastern Greater Iran as evidenced from names in Avestan geography.

After Avestan became extinct, its religious texts were transmitted orally, then collected and put into writing during the Sasanian period (c. 400 – 500 CE). The extant material falls into two groups: Old Avestan (c. 1500 – 900 BCE) and Younger Avestan (c. 900 – 400 BCE). The immediate ancestor of Old Avestan was the Proto-Iranian language, a sister language to the Proto-Indo-Aryan language, with both having developed from the earlier Proto-Indo-Iranian language. As such, Old Avestan is quite close in both grammar and lexicon to Vedic Sanskrit, the oldest preserved Indo-Aryan language.

Indo-Aryan peoples, also known as Indic peoples, are a diverse collection of peoples predominantly found in South Asia, who (traditionally) speak Indo-Aryan languages. Historically, Aryans were the pastoralists who spoke Indo-Iranian languages, migrated from Central Asia into South Asia, and introduced the Proto-Indo-Aryan language. The early Indo-Aryan peoples were known to be closely related to the Iranian group that have resided west of the Indus River; an evident connection in cultural, linguistic, and historical ties. Today, Indo-Aryan speakers are found south of the Indus, across the modern-day regions of Bangladesh, Nepal, Pakistan (east of Indus River), Sri Lanka, Maldives and northern half of India.