1. Raja yoga. Sometimes called 'Raja' or the 'King' of yoga practices, it focuses on meditation and is based on the eight-limbs leading toward enlightenment as outlined in Patanjali's Yoga Sutra. Those who enjoy time alone or time in nature are naturally drawn to Raja yoga.
2. Hatha yoga. Hatha yoga uses the body as the vehicle for self-liberation. It is ideal for those who find that sitting in meditation is too challenging. Working with the body via the poses is their way of generating self-realization.
3. Jnana yoga. This is the path of wisdom and involves disciplined study of texts combined with inquiry into one's true self. It's often called "yoga of the mind" and is well suited for persons inclined toward academics and intellectual interests.
4. Karma yoga is the yoga of action such as helping the poor, addressing social injustices and promoting equality for all. Selfless service is key to karma yoga and those who engage in it, work to remain completely detached from outcomes and results. Social activists are an example of people doing karma yoga.
5. Bhakti yoga is the yoga of devotion which seeks and finds liberation in love and total surrender to the Divine. Christian mystics are good examples of those who practice Bhakti yoga.
6. Mantra yoga is the yoga of sound. It is the practice of becoming centered and focused through chanting and the repetition of empowered sounds. The most important and powerful mantra is OM though there are many others.
7. Tantra yoga uses ritual, visualization, aspirations and subtle energy work to achieve liberation. It is especially refined and practiced by Tibetan Buddhists.
Most committed yogis utilize some combination of these seven branches for their spiritual growth and evolution. Only a few work with just one style.