This art of right living was perfected and practiced in India thousands of years ago and the foundations of yoga philosophy were written down in The Yoga Sutra of Patanjali, approximately 200 AD. The core of Patanjali’s Yoga Sutra is an eight-limbed path that forms the structural framework for yoga practice.
In the video below Deepak Chopra gives a very brief description of the 8 limbs.
The 8 limbs are:
Yama : Universal morality
Niyama : Personal observances
Asanas : Body postures
Pranayama : Breathing exercises, and control of prana
Pratyahara : Control of the senses
Dharana : Concentration and cultivating inner perceptual awareness