Pilates has, during the last few decades, become one of the most popular forms of exercise. Whether all exercise sold as Pilates today is true to the original system invented by Joseph Pilates (born in Germany in 1883) is questionable.
Quote from: http://en.wikipedia.org/wiki/Pilates#Legal_action:
"In recent years the term “Pilates” has entered the mainstream. Following an unsuccessful intellectual property lawsuit, a US federal court ruled the term “Pilates” generic and free for unrestricted use. As a result, anyone, trained or untrained, can offer “Pilates” as a service to the public. Consequently, people may face extensive and conflicting information about what Pilates is, how it works, and what credentials they should seek in an instructor."
According to Philip Friedman and Gail Eisen Pilates who published the first modern book on Pilates, "The Pilates Method of Physical and Mental Conditioning", in 1980, the Pilates method of exercise is based on the following six basic principles:
Those six pilates principles could easily be used to describe the principles of many kinds of yoga as well.The main difference between yoga and Pilates is that Pilates uses various type of equipment for resistance training.