There are several different types of yoga practiced today. Three popular forms are: Kundalini, Vinyasa and Hatha.
Kundalini Yoga, also called the Yoga of Awareness, is named after the Kundalini, or an energy thought to lie curled like a serpent at the base of the spine. The teachings say this serpent, or energy, is "sleep" or dormant. By practicing this type of yoga, the energy gradually "awakens," expanding your awareness.
Kundalini Yoga focuses on exercising the spinal and navel center in an effort to awaken the Kundalini energy stored in the spine. Breath is very important. Each asana should be practiced with a specific breath sequence.
Although it can be physically challenging, it is one of the more spiritual types of yoga. In addition to the Asanas, there are specific mantras, chanting, and meditation sequences.
Although it's been said Kundalini is over 5000 years old, almost all of what we know comes from a man named Yogi Bhajan. Bhajanrought his knowledge of Kundalini Yoga to the West in 1969 and taught until 2004.
Bhajan established 3HO (Healthy, Happy, Holy Organization) to continue his teachings.
Vinyasa means, "to place in a certain way," or "breath with movement." Vinyasa yoga is a dynamic, flowing form of yoga that focuses on the synchronization of movement and breath. The purpose of this focus is internal cleansing.
As you flow from asana to asana, you move on the inhale or the exhale. Vinyasa, or Flow, is one of the more fast-paced types of yoga. It's also full of variation. Each teacher will have a little different "flow." Compare this to Bikram yoga, which is always the exact same pose sequence.
Dubbed the "father of modern yoga," Sri T. Krishnamacharya brought Vinyasa-Ashtanga yoga to the modern world. Born in 1888, Krishnamacharya had four students, one of which was named Parrabhi Jois. Jois went on to create the Ashtanga Yoga Institute where he teaches and practices Vinyasa Flow.
Hatha means willful or forceful. It also means Sun Moon, representing the opposites of masculinity / femininity, day / night, winter / summer, active / passive etc. Hatha is the best known of the 6 major branches of yoga which include Tantra, Karma, Raja, Bhakti, and Jnana yoga.
Hatha is generally a slower form focusing on stretching and holding poses. The poses are generally held for 15-30 seconds with conscious breathing.
Hatha can easily be traced back to at least the 15th century. The book, Hatha Yoga Pradipika, written by Svami Svatmarama, is thought to be the classic guide to yoga.