Sruti, meaning 'that which is heard,' refers to the revealed scriptures of Hinduism - primarily the four Vedas (Rig, Sama, Yajur, Atharva) - believed to be of divine origin without human author composition. Smriti ('that which is remembered') refers to texts of human authorship like the Mahabharata, Ramayana, and Manusmriti. Brahmanas and Upanishads are actually parts of the Sruti tradition.