Classes of Tantra in Tibetan Buddhism

Classes of Tantra in Tibetan Buddhism refers to the categorization of Buddhist tantric scriptures in Indo-Tibetan Buddhism. Tibetan Buddhism inherited numerous tantras and forms of tantric practice from medieval Indian Buddhist Tantra. There were various ways of categorizing these tantras in India. In Tibet, the Sarma (New Translation) schools categorize tantric scriptures into four classes, while the Nyingma (Ancients) school use six classes of tantra.