For nearly 2000 years, Sanskrit was the language of a cultural order that exerted influence across South Asia, Inner Asia, Southeast Asia, and to a certain extent East Asia. A significant form of post-Vedic Sanskrit is found in the Sanskrit of Indian epic poetry—the Ramayana and Mahabharata. The deviations from Pāṇini in the epics are generally considered to be on account of interference from Prakrits, or innovations, and not because they are pre-Paninian. Traditional Sanskrit scholars call such deviations ārṣa (आर्ष), meaning 'of the ṛṣis', the traditional title for the ancient authors. In some contexts, there are also more "prakritisms" (borrowings from common speech) than in Classical Sanskrit proper. Buddhist Hybrid Sanskrit is a literary language heavily influenced by the Middle Indo-Aryan languages, based on early Buddhist Prakrit texts which subsequently assimilated to the Classical Sanskrit standard in varying degrees.
What are prakritisms?
borrowings from common speech