The word Yoga means to join, unite or merge. It is derived from the sanskrit root Yui. Yoga is a science and an art. The practice of Yoga integrates the body with the mind and the mind with the soul, thereby helping us to understand our own nature and to live harmoniously with our fellow men.
Yoga can be practiced by all irrespective of race, colour, creed, sex and age. Most people are aware of only two aspects of Yoga, the asanas and meditation. Yoga is more than these two aspects. It is, in fact, an eight-fold path called Ashtanga Yoga.
The eight limbs of Yoga are:
1. Yama – Percepts of social discipline
- Ahimsa – Non-violence
- Satya – Truth and honesty
- Asteya – Non-stealing, non-covetousness
- Brahmacarya – Continence and self-control
- Aparigraha – Non-accumulation of needless wealth
2. Niyama – Percepts of individual discipline
- Sauca – Cleanliness and purity
- Santosa – Satisfaction and contentment
- Tapas – Austerity, ability to bear hardship
- Svadhyaya – Introspection, self-study. Spiritual self-education
- Isvara pranidhana – Surrender of the self to God. Acknowledgement that there is a higher principle in the universe than one‘s own small self
3. Asana – Postures, integration of mind and body through physical activity
4. Pranayama – control of breathe and energy, leading to integration of body and mind
5. Pratyahara – Withdrawal of the senses of perception from their objects
6. Dharana – Intense concentration for developing inner vision
7. Dhyana – Meditation, uninterrupted and deep concentration for a long period
8. Samadhi – The goal of Yoga, attained after a prolonged period of dhyana. Just as a river merges into the ocean and becomes one with it, so also the individual self merges into the Universal Spirit and becomes one. Peace and happiness are expected as all polarities such as pain, pleasure, good and bad vanish.
Hatha means force or determination. Force and determination are required to practice Hatha Yoga. In addition ‘ha’ means sun and ‘tha’ means moon. Just as positive and negative currents produce energy, Hatha Yoga also produce energy and force. That practice will lead us to more health, energy and happiness in every day life.
 From the ancient Yoga Sutras of Patanjali, more information under http://en.wikipedia.org/wiki/Yoga_Sutras_of_Patanjali.
Text source, modified: Swati and Rajiv Chanchani, Yoga for Children.