The word yoga itself means "union": of the individual consciousness or soul with the Universal Consciousness or Spirit. There are various paths of Yoga that lead toward this goal, each one a specialized branch of one comprehensive system:
Hatha Yoga - a system of physical postures, or asanas, whose higher purpose is to purify the body, giving one awareness and control over its internal states and rendering it fit for meditation.
Karma Yoga - selfless service to others as part of one's larger Self, without attachment to the results; and the performance of all actions with the consciousness of God as the Doer.
Mantra Yoga - centering the consciousness within through japa, or the repetition of certain universal root-word sounds representing a particular aspect of Spirit.
Bhakti Yoga - all-surrendering devotion through which one strives to see and love the divinity in every creature and in everything, thus maintaining an unceasing worship.
Jnana yoga - (pronounced "Gyana Yoga") - the path of wisdom, which emphasizes the application of discriminative intelligence to achieve spiritual liberation.
Raja Yoga - the royal or highest path of Yoga, formally systematized in the second century B.C. by the Indian sage Patanjali, which combines the essence of all of the other paths.
(The above is an excerpt from the Preface to "The Yoga of the Bhagavad Gita" by Paramahansa Yogananda)
"The Bhagavad Gita teaches every important aspect of the spiritual path: during activity, Karma Yoga (the yoga of right action); during thinking and discrimination, Gyana Yoga (the yoga of wisdom and discrimination); when feeling and experiencing emotion, Bhakti Yoga (the yoga of devotion). There is a central teaching, however, in the Bhagavad Gita, which unites all paths even as subsidiary streams unite in a large river.
"That river," Yogananda said, "is the energy flowing in the spine. The subsidiary paths of yoga offer guidance to people of different basic temperaments: the active;, the discriminating, the 'heartful.' The central river to enlightenment, however, is shown by Raja Yoga, the royal yoga: the pathway of the spine."
(Quoted from the Introduction to "the Essence of the Bhagavad Gita" by Swami Kriyananda)
Anant Yoga is a form of Raja Yoga.
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