All Vedic science believes that words possess divine powers and when they are properly recited, they can wield infinite power that can be used to accomplish anything. This is because of the scientific belief that words are made of vibrations which concentrate their energy and when that energy is unleaHed in a proper manner, anything can be achieved, giving rise to Tantra Mantra Yantra Vigyan.
Tantra shastra is a serious and detailed science. All the sadhnas that it includes is extremely deep and mysterious. The significant aim of Tantric Sadhna is to attain a balanced and equivocal result while the biggest obstacle in this path is our body itself. The sadhna is based on two factor te body and soul. In reality there are not separate. When one starts practicing the sadhna the body is that part of the soul which can be controlled by the senses and the soul is that part of the body which the senses cannot control. Hence the visible end is the body and the invisible is the soul. Tantra sadhna is the sadhna of these two ends. In the mid of the body and soul is the MIND. The mind and the body are both dependant. Body can never be free. The mind while being dependant can be made free via sadhna. The soul on the other hand is always independent and free, and can never be independent. Therefore the mode by which one goes from dependence to independence is the Tantra shastra a definite system.
The other meaning of Tantra is thread or tantu. That is each thread in the cloth representing the universe and how where and why each thread to be arrange answers relating to this. This whole system is based on Lord Shiva's teachings. Aardhnarishwar Shiva is the ideal for this shastra. Devi Parvati is maya. Even in presence of the maya, Lord Shiva attains Samadhi, the path which even in presence of maya can lead one towards Samadhi is called Tantra. The Tantra teaches man how he can become Shiva (God) from being a Jeeva (human). Just like the spider he waves the web and sits in the center, god also creates the universe and watches over it from its center. Like many lines can be drawn from the periphery of a circle to the center point to help you reach the center. All creatures have to use different paths to reach god.