What is Tantra?
from Ecstasy Through Tantra by Dr. John 
Mumford
A simple question without a simple answer, and any attempt at definition will necessarily be incomplete. The roots of the word are Sanskrit:
tan- thread, web, stretch, spread or expand, and
tra -tool or instrument.
Tantra - tool for expansion or a weaving
Through Tantric practice one can experience an expansion of consciousness and recognize the interconnectedness of the web of existence.
At the same time, Tantra can refer to any of a number of sacred texts in the Hindu, Jain and Tibetan Buddhist traditions. Many of these texts contain detailed guidelines for spiritual practice. From this perspective, Tantra is a vast body of spiritual and physical knowledge, encompassing an array of practices, including all forms of yoga. These practices are aimed at expanding consciousness and liberating oneself "through life and not through escape, using the body as an instrument."
In Tantra, the energies of the body are used as the fuel for spiritual development.
In the West, Tantra is often called the "Yoga of Sex." While there is a kernel of truth in this phrase, the popular press has created a misleading impression that Tantra is about having better orgasms or about becoming a better lover. Since Tantric practices are designed to expand consciousness, they can expand a person's capacity to give, receive and experience pleasure, not only in the sexual realm but in all areas of life, provided that person is willing
to do the work.
Many Western Tantra teachers emphasize very powerful techniques for enhancing sexual pleasure and intimacy, while some traditional teachers discourage students from exploring sexual Tantra at all.
Tantra is... by Osho
'Tantra is not teaching sexuality. It is simply saying that sex can be a source of bliss.
And once you know that bliss, you can go further because now you are grounded in reality.
One is not to remain in sex forever, but you can use sex as a jumping point. That is what Tantra means: you can use sex as a jumping point.
And once you understand the ecstasy of sex, you can understand what mystics have been talking about--a greater orgasm, a cosmic orgasm' Tantra is the total surrender, or letting go of all mental, emotional and cultural conditioning, so that universal life energy may flow through you like a river without any effort. It is a letting go to a universal oneness...to love. When fear is removed, Tantra remains. The word "Tantra" has many definitions, and perhaps its real meaning has been lost to antiquity. Some say it comes from the Sanskrit or Hindi word for fabric or tapestry, meaning that it is woven into one's life. Others say that it comes from two Sanskrit words, Tanoti and Trayati - Tanoti means to expand consciousness, and Trayati means to liberate consciousness. One might then say that Tantra expands and liberates consciousness. The highest possible synthesis between love and meditation, Tantra is also the connection between the third dimension and other planes of existence beyond mere materiality. While not a religious philosophy, Tantra embraces a deep spiritual understanding of life, and an ancient art of living in harmony with existence.It is treating sexual energy as a friend, rather than something to be suppressed or talked about in low tones. It does not deny sex, or consider sex a hindrance to enlightenment or Heavenly Grace. To the contrary, Tantra is the only spiritual path which says that sex is sacred and not a sin. Tantrikas are God-loving rather than God-fearing. There is a most beautiful word for sex in the Sanskrit language, and that is Kama which means sex/love together, undivided and indivisible. Most everyone is familiar with the classic Kama Sutra, the 7th Century Tantric scripture. Kama is also the name for the Hindu Goddess of love... and love is what Tantra encourages-total love, including the mind, the spirit and the body. Let It All Go! MeditationConscious thought, at least the way we usually do it, is the manifestation of ego, the you that you usually think that you are. Conscious thought is tightly connected with self-concept. The self-concept or ego is nothing more than a set of reactions and mental images which are artificially pasted to the flowing process of pure awareness.Tantra seeks to obtain pure awareness by destroying this ego image. This is accomplished by a process of visualization. The student is given a particular religious image to meditate upon, for example, one of the deities from the Tantric pantheon. He does this in so thorough a fashion that he becomes that entity. He takes off his own identity and puts on another. This takes a while, as you might imagine, but it works. During the process, he is able to watch the way that the ego is constructed and put in place. He comes to recognize the arbitrary nature of all egos, including his own, and he escapes from bondage to the ego. He is left in a state where he may have an ego if he so chooses, either his own or whichever other he might wish, or he can do without one. Result: pure awareness. Tantra is not exactly a game of patty cake either.