Sacred texts of Hinduism mostly written in Sanskrit. Hindu scripture is divided into two categories: Śruti – that which is heard (i.e. revelation) and Smriti – that which is remembered (i.e. tradition, not revelation). There are two types of Hindu scriptures: Hindu religious texts and Hindu classical texts. Conventionally, Hindu literature group into two categories: Shruti - that which is revealed and Smriti - that which is learned. The Vedas constituting shruti, are considered divinely revealed and are thus sacred scripture. Later texts, like the various shastras, itihaasas, and Puranas form smriti. All shruti scriptures are composed in Sanskrit.
There are four vedas (Rigveda, Yajurveda, Samaveda and Atharvaveda) and each veda has four types of texts associated with it: Samhita (veda proper), Brahmanas, Aranyakas and Upanishads. Usually, there are more than one shakha (recension) of a single samhita. For example, Yajurveda has two: shukla Yajurveda and krishna Yajurveda. Sometimes the materials are mixed. For example in the krishna Yajurveda the samhita verses are interspersed with the brahmana material. The Brihadaranyaka Upanishad is considered as both an aranyaka as well as an upanishad.