Sivananda Yoga is a form of Hatha Yoga which focuses on five points:

Proper exercise (asanas)
Proper breathing (pranayama)
Proper relaxation (savasana)
Proper diet
Positive thinking and meditation

The Sivananda group was founded in 1961 by the late Swami Vishnu Devananda, who was a disciple of Swami Sivananda.

Swami Vishnu Devananda wrote ‘The Complete Illustrated Book of Yoga’, a long-time best seller and was recognised as a world authority on the subject. The Sivananda group has 20 yoga centres and 10 ashrams around the world.