Original classical texts state that there are 4 types of yoga: 1. Raja Yoga (which includes ALL westernized forms of physical yoga uch as flow yoga, hot yoga, heart yoga, tantra yoga etcetera...all YOGA is under the classification of Raja Yoga). Raja yoga is the yoga of concentration/meditation. 2. Jnana Yoga - or yoga of intellect 3. Karma Yoga - Yoga of selfless service to others 4. Bhakti Yoga - or the Yoga of devotion to God. All yoga has the purpose of helping us to know and understand the divine God. One should balance all 4 types of yoga and it will help us to know and love God. When learning about the various forms of yoga one can be easily confused as the western world has changed the meaning of yoga and turnd it into a marketing game. The true classical forms of yoga as developed in India is represented on the following website: go to www.sivananda.org