Tantras ("Looms" or "Weavings") refers to numerous and varied scriptures pertaining to any of several esoteric traditions rooted in Hindu and Buddhist philosophy. The religious culture of the Tantras is essentially Hindu, and Buddhist Tantric material can be shown to have been derived from Hindu sources. And although Hindu and Buddhist Tantra have many similarities from the outside, they do have some clear distinctions. The rest of this article deals with Hindu Tantra. Buddhist Tantra is described in the article on Vajrayana.
The word tantra is made up by the joining (sandhi in Sanskrit) of two Sanskrit words: tanoti (expansion) and rayati (liberation). Tantra means liberation of energy and expansion of consciousness from its gross form. It is a method to expand the mind and liberate the dormant potential energy, and its principles form the basis of all yogic practices. Hence, the Hindu Tantra scriptures refer to techniques for achieving a result.
The Hindu Tantras total ninety-two scriptures; of these, sixty-four are purely Abheda (literally "without differentiation", or monistic), known as the Bhairava Tantras or Kashmir Śaivite Tantras, eighteen are Bhedābheda (literally "with differentiation and without differentiation" monistic or dualistic), known as the Rudra Tantras), and ten are completely Bheda (literally "differentiated" or dualistic), known as the Śiva Tantras. The latter two (Rudra Tantras and Śiva Tantras) are used by the Śaiva Siddhāntins, and thus are sometimes referred to as Shaiva Siddhanta Tantras, or Śaiva Siddhānta Āgamas.
In the Nāth Tradition, legend ascribes the origin of Tantra to Dattatreya, a semi-mythological yogi and the assumed author of the Jivanmukta Gita ("Song of the liberated soul"). Matsyendranath is credited with authorship of the Kaulajñāna-nirnāya, a voluminous ninth-century tantra dealing with a host of mystical and magical subjects. This work occupies an important position in the Hindu tantric lineage, as well as in Tibetan Vajrayana Buddhism.
In contradistinction to the Vaidik ritual, which is traditionally performed out-of-doors without any idols nor emblems, the Tantrik ritual is largely a matter of temples and idols. The Tantras are largely descriptions and specifications for the construction and maintenance of temple-structures together with their enclosed idols and lingas—an example of type of text is the Ajita Māhātantra. Another function was the conservation as state-secrets of texts for use by royalty to maintain their authority through rituals directed to deities controlling the political affairs-of-state—an example of this is the Śārada-tilaka Tantra.
Tantric texts are usually associated with a particular tradition and deity. The different types of Tantric literature are tantra, Āgama, saṃhitā, sūtra, upaniṣad, purāṇa, tīkā (commentaries), prakaraṇa, paddhati texts, stotram, kavaca, nighaṇṭu, koṣa and hagiographical literature. They are written in Sanskrit and in regional languages. The major textual Tantra traditions with some key exemplary texts is as follows:
Sir John Woodroffe translated the Tantra of the Great Liberation (Mahānirvāna Tantra) (1913) into English along with other Tantric texts. Other tantras which have been translated into a Western language include the Malini-vijayottara tantra, the Kirana tantra, and the Parakhya Tantra.