The basic difference between unenlightened sexuality and Tantra is that sex becomes sacred and divine when you approach it from your heart and body, rather than solely from your mind. When we embrace Tantra, we become more "complete." By identifying and stimulating our innate sensual spirituality, we discover parts of ourselves that have been repressed. We can learn to use Tantric energy for sexual pleasure and awareness above all. Tantra doesn't tell you to control your sexual urges to reach God, but rather the opposite. It supports the development of this vital energy to achieve union with Divinity. The essence of Tantra is the full expression of existence... a merging with, rather than a withdrawing from. In Tantra, sexual energy is used as ignition for firing the Kundalini energy, the body's biological energy system, merging it/you with universal energy.
Familiarity with Tantra can help a person enjoy their sex life to its fullest potential. It can help do away with guilt or fear, and break down self-imposed or limiting cultural boundaries.
Tantra teaches us to become familiar with our mystical nature, and when we do so, our boundaries (sexual and otherwise) expand. We enter into new realms of awareness. We become empowered and more fulfilled -- and the orgasms experienced in this state of consciousness are not just incredible, they're explosive and potentially unending.