There are many styles of yoga, and nearly all of them are rooted in hatha yoga, which focuses on developing control of the body through poses. (asana).

Whether you prefer a gentle yoga or a more active one such as Ashtanga, practicing any style of yoga is beneficial. Many studios will allow you to attend the first class for free. This will give you the opportunity to decide if you like the environment, style and teaching methods.

Here are brief descriptions of the most common types of yoga.

Ananda, which means "joy" in Sanskrit, was founded in 1968 by J. Donald Walters (Swami Kriyananda) to support others in their quest for spiritual growth.
Ananda Yoga is a classical approach to yoga that includes:
Asana (yoga postures)
Pranayama (special breathing exercises)
Meditation techniques
Yoga philosophy

Anusara: Heart-oriented.
This particular style of yoga was founded by John Friend in 1997. Anusara yoga has an uplifting philosophy that looks for the good in all people and all things. Students of all levels of ability and yoga experience are honored for their unique differences, limitations, and talents.

Anusara an elegant system of alignment principles, and is fast growing with over 1200 affiliated teachers and 100,000 students world-wide.

Ashtanga: the Power of yoga.
This method of Yoga was developed by Sri K. Pattabhi Jois in Mysore, India. It involves synchronizing the breath with a progressive series of postures which builds heat in the body and causes toxins to be released. The result is improved circulation, a light and strong body, and a calm mind. This is an active and powerful yoga.

Bhakti Yoga or devotional Yoga.
This is a choice for those who are predominantly seeking emotional fulfillment and well being. The "bhakta" usually practices meditation by visualization. This flow of life force brings about a superconscious state of awareness which is generally called a mood, or bhava.

Because of the focus of the mood and mind relationship, the bhakta is given special ability to experience the deep samadhis and other high states of awareness which other yogis focus upon.

Bikram: Turning up the heat - to dangerous levels.
Bikram Choudhury, known as the yoga teacher to the stars, developed this hot yoga practice. Be prepared to sweat in this one. The bikram class turns up the room temperature to anywhere from 85 degrees to 105 degrees. In this hot and steamy environment, students perform, always in the same order, 26 poses designed to cleanse the body from the inside out. This is a vigorous workout.

NOTE: Bikram Yoga has been the subject of much debate as to whether or not performing strenuous exercise in a room over 100 degrees Fahrenheit is safe. It is possible - and has occurred - for Bikram practitioners to experience dizziness and nausea. If the yoga practitioner ignores these warning signs then far more serious conditions can arise, including dehydration, heat stroke, and in rare cases, even death.

An article published by Yogacharya Vishwas Mandlik (Vice Chancellor) Yoga University India & Dr.Sujit Chandratreya (MD, DNB, DM, Endocrinologist & Diabetologist) explains:
“Yoga is relaxation and not like stressful exercises. If the Asana is practiced in a hot environment ( about 105 degrees F.) as it is done in some styles of Yoga, the heart rate, respiration rate and blood pressure increases, though muscles expand and one can stretch the body more, this may harm the muscles. Ideally the Yoga should be practiced in normal environmental conditions.

This Hot Yoga, Bikram yoga or similar type is inappropriate and difficult to justify version of Indian ancient Science of Yoga. In fact it can not be called as Yoga as per Indian Science.

Many medical experts all over the world have raised concern over the excess strain exerted on muscles in Hot environment (temperatures about 105 deg. F). In this environment there is always a danger of muscle or ligament stretched beyond biological limit and may get Damaged.

Consider the Fever; it is a natural protective phenomenon as many bodily reactions are accelerated by heat. Thus in any infection, we get fever and it helps to clear that infection. It also dilates our blood vessels and makes the heart beat faster and stronger. It also causes excessive water loss from our body.

But there is another side of it! Our body has very little redundant energy to waste away. The energy demand in heated environment catalyzes certain bodily processes and slows down other processes. Our present medical science does not have a complete knowledge about it, but it is very logical that heated environment is not natural or normal condition for the body. Our body is meant to function at normal temperatures; Yoga should be practiced in optimum & comfortable conditions.

Imagine doing Yoga when you are suffering from Fever where your body temperature is 105 deg. Fahrenheit! Life is very difficult in regions where temperatures are as high as 48 degrees Celsius, so why create such difficult condition around and practice yoga there? Isn’t it a common sense not to create worse situations for body?”

Integral: the healing power of relaxation.
This school of yoga is associated with two prominent figures: Swami Satchidananda, and his student, Dr. Dean Ornish, who uses integral yoga as part of his treatment of heart patients. The main belief of Integral Yoga is that through yoga, it is possible for man to become aware of his True Self. Integral Yoga teaches its followers five paths to self-realization.
These five paths include Hatha Yoga, Karma Yoga, Bhakti Yoga, Jnama Yoga, and Raja Yoga.

Hatha Yoga: the yoga of vitality and physical health.
Hatha yoga refers to a set of physical exercises (known as asanas or postures), and is the form that most Westerners think of as "yoga."

In fact, it is the foundation of all Yoga systems. It is a system of yoga introduced by Yogi Swatmarama, a yogic sage in the 15th century in India, as a means of exercising, stretching, and freeing the body so it can be healthy.

The word "hatha" comes from the Sanskrit terms "ha" meaning "sun" and "tha" meaning "moon". Hatha yoga strives to balance these two elements which represent the masculine and feminine, strength and flexibility. The word yoga, from the Sanskrit word yuj means to yoke or bind and is often interpreted as "union" or a method of discipline.

The Hatha yoga predominantly practiced in the West consists of mostly asanas (postures).

Iyengar: Symmetry and alignment.
B.K.S. Iyengar developed this yoga style, which stresses understanding the body and how it works. Students focus on symmetry and alignment, using props — such as straps, blankets, wooden blocks, and chairs — to achieve postures. Each pose is held for a longer amount of time than in most other yoga styles.

Teachers of this discipline must go through an intense, long, and rigorous training program.

Kripalu: The yoga of consciousness.
Kripalu emphasizes proper breath, alignment, coordinating breath and movement, and “honoring the wisdom of the body.” Developed by Yogi Amrit Desai, Kripalu takes the student through three stages beginning with the steady practice of postures (stage one), then holding the postures longer and developing concentration and inner awareness (stage two), and finally surrendering to the body’s own wisdom (stage three).

Ultimately kripalu leads to the experience of meditation-in-motion — actually doing postures spontaneously and unconsciously.

Kriya Yoga
Classically, kriya Yoga is a blend of raja, jnana, and bhakti practices. The word kriya means "to do, to make an effort," or "to transform."

One of the main ways that kriya is practiced in a daily program of self-discipline of mind and body, and introspection. All forms of kriya are deeply related and very ancient — well over five thousand years old and probably much older. Several million people practice both forms of kriya Yoga throughout the world today.

In meditation you learn, through practice, to overcome the tendency to be self-deluded, or to live a self-destructive life. Freeing your body of tension and your mind and emotions of turbulence, you discover your true self and dwell in it. You find more from life than you ever dared dream. These are the possibilities of your life through Yoga.

Kundalini: Awakening energy.
Once a guarded secret in India, kundalini yoga arrived in the West in 1969, when Sikh Yogi Bhajan challenged tradition and began to teach it publicly. This practice is designed to awaken kundalini energy, which is stored at the base of the spine and often depicted as a coiled snake. Kundalini mixes chanting, breathing practices, and yoga exercises. The emphasis is not on asana, but rather on chanting and breathing.

Kundalini should always be taught by a teacher who practices and understands this powerful yoga.

Sivananda: encouraging a Healthy lifestyle.
Sivananda yoga offers a gentle approach, which takes the student through the twelve sun salutation postures and incorporates chanting, meditation, and deep relaxation in each session.

Teachers encourage students to embrace a healthy lifestyle that includes a vegetarian diet and positive thinking with meditation. This style of yoga was founded by Swami Vishnu-devananda, who published in 1960 one of the classics of yogic literature, The Complete Illustrated Book of Yoga.

Tantra: Sensual spirituality.
Perhaps the most misunderstood yoga style, tantra is not about sexual indulgence. Rather, it is about discovering and stimulating sensual spirituality. This yoga works with the highly charged kundalini energy and, therefore, should always be guided and taught by a teacher.

Tantra teaches practitioners how to use this energy for sexual pleasure, for bringing joy and wholeness to everyday life, and for aiding in spiritual evolution. Tantra yoga includes visualization, chanting, asana, and strong breathing practices.

Viniyoga: Gentle flow.
This gentle form of flow yoga places great emphasis on the breath and coordinating breath with movement. Viniyoga’s flowing movement or vinyasa is similar to ashtanga’s dynamic series of poses, but is performed at a greatly reduced pace and stress level.

Poses and flows are chosen to suit the student’s abilities. It teaches the yoga student how to apply the tools of yoga — asana, chanting, pranayama (control of breath), and meditation — in individual practice.

Developed by T.K.V. Desikachar, the son of Krishnamacharya (teacher to some of the great yoga instructors including Iyengar and Pattabhi Jois), Viniyoga places less stress on joints and knees since postures are done with slightly bent knees. Viniyoga is considered excellent for beginners, and is increasingly being used in therapeutic environments.

This section was compiled by using classic books and the knowledge of teachers and Yogis.     We have tried to summarize the various styles of Yoga, which may omit some details.