The Yoga Sutras of Patanjali is a compilation of classical yoga teachings that were passed down orally before Patanjali (also known as the 'father of yoga') recorded them.
Believed to be over 4000 years old, there are 196 sutras (literally meaning 'thread') that describe what yoga is, why it is important, how to practice it and what might come as a result of regular practice. It's teachings include ethics, meditation, physical postures and directions for dealing with obstacles and every day life.
The text is a lot to contemplate in one go! It is intended to be referred to again and again; at different times in your life and yogi journey, different sutras will speak to you.
These eight steps basically act as guidelines on how to live a meaningful and purposeful life. What Patanjali has described as the completion of the yogic path is what, deep down, all human beings aspire to: peace.