Yoga is one of six schools of Hindu philosophy that scholars believe originated in India.  Yoga is not a religion, but enhances all belief systems.

Archaeologists believe Yoga is 5000 years old because of a carving found from the Indus Valley Civilization.  The carving depicts a figure that represents a yogi sitting in meditation posture.  The figure is shown sitting in a traditional cross-legged yoga pose with its hands resting on its knees.  The discoverer of the seal, archaeologist Sir John Marshall, named the figure Shiva Pashupati. 
 
The word Yoga first appeared about 3500 years ago in the Rig Veda, a collection of hymns and mantras.  This sacred scriptures defines Yoga as yoking or discipline, but offers no systematic practice. 
 
In the beginning Yoga was an oral tradition taught by teacher to student in the Sanskrit language. 
 
The philosopher/writer  Patanjali was the first to bring a systematic presentation of Yoga into written form with the Yoga Sutras.  The Sutras may have been written anywhere from 200 BCE – 400 CE.  This text contained 195 short phrases regarding daily living, beginning with how to conduct oneself in society and culminating in the act of final liberation or enlightenment. It also outlined the eight limb path of Yoga that is still practiced today.  Patanjali is considered the father of modern day Yoga. 
 
Hatha Yoga is one of six distinct branches of the yoga tree.  Hatha Yoga is where the physical postures the Western world now embraces, first appeared in the ninth or tenth century.
 
The name Hatha Yoga, a combination of “ha” meaning sun, and “tha,” meaning moon, denotes the union of opposites.  Hatha also means determined effort and yoga, translates as joining together.  Therefore, hatha yoga implies that it takes a lot of effort to unify opposing forces and bring together the body and the mind. 
 
The other five branches of Yoga are Karma Yoga (service), Bhakti Yoga (devotion), Raja Yoga (meditation), Tantra Yoga (ritual) and Jnana Yoga (knowledge).
 
Many branches overlap.  You don’t have to be limited.  You may practice hatha yoga (taking care of one’s physical body) while, at the same time, living the lifestyle of a karma yogi – volunteering with organizations such as the Peace Corps or Habitat for Humanity.