Yoga is one of the most ancient spiritual concepts of East, and despite a philosophical look it has an equally significant physical basis. It is not a body of doctrines, theories or principles. Intellectual problems or inquiries as to 'why' or 'whence' are not the areas of yogic deliberations. Boiled down to basics, Yoga is a collection of simple practices, a kind of body rituals, consisting of action, method and technique.
The Bhagvad Gita clarifies this interpretation and lays stress upon the Karma Yoga. This scripture says
'Work alone is your privilege, never the fruits thereof. Never let the fruits of action be your motive; and never cease to work. Work in the name of the Lord, abandoning selfish desires. Be not affected by success or failure. This equipoise is called Yoga.'
The Kathopnishad describes Yoga thus :
According to B.K.Iyenger,