Shruti

Śruti or shruti in Sanskrit means "that which is heard" and refers to the body of most authoritative, ancient religious texts comprising the central canon of Hinduism. Manusmriti states: Śrutistu vedo vijñeyaḥ meaning, "Know that Vedas are Śruti". Thus, it includes the four Vedas including its four types of embedded texts—the Samhitas, the Upanishads, the Brahmanas and the Aranyakas.