In yogic literature the term Hatha is derived from two Sanskrit mantras ‘HAM’ and ‘TAM’. Ham represents the active force or the solar force in our body, whereas Tam represents the moon force or the passive force in our body. As per yoga, these two forces are known as Pindla and Ida. And the whole subject of hatha yoga is bringing the balance between both the forces.
These two forces are constantly working in our body; because of the interaction of these two forces with each other, we breathe, we eat, we live and we think. So, yogis felt that these two forces have to be balanced to raise the level of our consciousness.
The whole subject of Hatha yoga comprises of six purification techniques namely Nethi, Bhasti, Bhavati, Navali, Kapalbhati and Trataka. Later, the thinkers and writers who wanted the Hatha yoga to become a complete science of yoga, added few more things in it. The practices of asana, the postures, and the practices of pranayama and techniques of breathing were added to it. This made it a complete science of yoga, as reported in indiainteracts.