This is a well-done 9 minute video of South African Iyengar Yoga teacher, Judy Farah, explaining what Iyengar Yoga is. She talks about the philosophy, history, and benefits from practicing this style of yoga.
Judy mentions that she has been practicing yoga since she was quite young, but it was when she was about 40 years old that she experienced Iyengar Yoga for the first time, and she knew this was the style that she was meant to continue with.
Her characterization of Iyengar yoga is that the practice of yoga asanas (postures) in this method is more precise than in other methods, and the poses are held for longer.
Judy gives a good overview of why B.K.S. Iyengar introduced the use of props in this method of yoga:
B.K.S. Iyengar was seeing that people were doing the postures incorrectly, and often injuring themselves, but if they were made to use props for support and assistance, people were able to develop better alignment in the poses, with less chance of injury, and with greater benefits.
Judy also reminds us that the practice of yoga is not just physical. This practice affects us on all levels of our being.
If you've been taking Iyengar Yoga classes for awhile, probably none of this is new to you, but it's a nice overview of this powerful method of practicing yoga.