Tantra is often misunderstood in the West as a solely sexual practice. It is actually a form of religion that has its roots in both Buddhism and Hinduism. There are significant differences between Buddhist and Hindu Tantra. Some Buddhists maintain that Hindu Tantra is derived from Buddhist Tantra, while many Hindus take the opposite view. However, it is not currently possible to state which one is older.
The main emphasis of the Tantra is the development of dormant higher senses using special meditations and rituals. Due to the esoteric nature of this practice, followers believe that this must be passed on personally from master to student. The Tantra emphasizes three areas of development, namely body coordination (gestures or Mudras), speech (Mantras), and the mind (meditation and creative visualization, or Yantras). Although practices differ between the Buddhist and Hindu Tantras, both stress the inner realization of the union of contrasting forms (the male/female symbolism).
The literal meaning of the Sanskrit word Tantra is "loom", from which the ideas of "thread" or "continuity" are derived. Its generally accepted meaning in the Indian religious context is roughly "special doctrines and practices." Although there are sexual practices in both Hindu and Buddhist Tantra, there are many, and indeed more, non-sexual practices. As far as Buddhist Tantric sexual practices are concerned, some teachers maintain that a physical partner is not necessary and may be replaced by a visualized or imaginary partner. Thus, Buddhist Tantra is about the rechanneling or redirection of energy.
References:
Bhattacharya, The World of Tantra (1988); N. N. Bhattacharya,
History of the Tantric Religion (New Delhi: Manohar, 1992);
Sudhakar Chattopadhyaya, Reflections on the Tantras (1978); A.
Mookerjee and M. Khanna, The Tantric Way: Art, Science, Ritual (1989);
H.V. Guenther, The Tantric View of Life (Berkeley and London:
Shambhala, 1972); and A. Bharati, The Tantric Tradition, Revised
edition (New York: Samuel Weiser, 1975).