Tantra
Tantra are the esoteric traditions of Hinduism and Buddhism that developed on the Indian subcontinent from the middle of the 1st millennium AD onwards. The term tantra, in the Indian traditions, also means any systematic broadly applicable "text, theory, system, method, instrument, technique or practice". A key feature of these traditions is the use of mantras, and thus they are commonly referred to as MantramΔrga in Hinduism or MantrayΔna and Guhyamantra in Buddhism. Starting in the early centuries of the common era, newly revealed Tantras centering on Vishnu, Shiva or Shakti emerged. There are tantric lineages in all main forms of modern Hinduism, such as the Shaiva Siddhanta tradition, the Shakta sect of Sri-Vidya, the Kaula, and Kashmir Shaivism. In Buddhism, the Vajrayana traditions are known for tantric ideas and practices, which are based on Indian Buddhist Tantras.