Tantra could be thought of as a set of hypothesises, spiritual practices and ritualistic actions that through personal effort and experimentation (sadhana) are designed to direct the universal energies of the macrocosm into the practitioner (sadhak) . The reason for undertaking such efforts is nothing less than total liberation from ignorance and suffering (Moksha).
One meaning of tantra is ‘to weave’. It is also taught that tantra is like the actual shuttle that moves between the threads when weaving a fabric, correctly implying that tantra can be a device or technology. The fabric itself represents the universe with all its subtle energies and all the myriad permutations of consciousness. This fabric of reality is like an interconnected matrix, and tantra then is the expansion of our consciousness wherein these interconnections are intuitively and experiential understood… the inner experience that everything is intrinsically woven together and is ultimately one occurrence.
This is partly why love-making can be such a powerful form of yoga because the added dimension of external polarity; the masculine working with the feminine which is created by being joined with a partner, heightens the experience of rising energy through the body and makes for a very unique practice which may not be achieve so readily working alone.