Yoga is a system of exercises practiced as part of the Hindu discipline to promote control of the body and mind and to reach a state of spiritual insight and tranquility. That state is achieved through the three paths of actions, knowledge and devotion.
Yoga is one of the six branches of classical Indian philosophy. The word yoga comes from the Sanskrit word “yuj,” meaning to yoke, join or unite. Its practice joins all aspects of the individual, body with mind and mind with soul. Although people think yoga is about stretching, it’s really about creating a balance within the body, and developing strength and flexibility is a part of creating this balance.
Yoga teachers refer to “your practice” or your individual experience with yoga over time. 
“Your practice” of yoga is always evolving and changing, so it will never get boring. Your relationship to the poses will change over time, even though the poses themselves remain the same. Anyone can start a yoga practice, regardless of their level of flexibility or strength. Flexibility and strength will develop over time. The idea of yoga as “your practice” encourages the noncompetitive spirit of yoga, teaching students to place their egos aside and to move with the flow of the poses. You are no more important than anyone else, and they are no more important than you; everyone is just doing their best on any given day.
There are eight limbs of yoga. Each limb relates to an aspect of achieving a healthy and fulfilling life, and each builds upon the one before it: 
- Yama: social restraints or ethical values
- Niyama: personal observance of purity, tolerance, and study
- Asanas: physical exercises (practicing the poses of yoga)
- Pranayama: breath control or regulation
- Pratyahara: sense of withdrawal in preparation for meditation
- Dharana: concentration
- Dhyana: meditation
- Samadhi: ecstasy