Yoga is a physical, mental and spiritual practice that originated in India, probably around the 6th and 5th centuries BC. It has been practiced in the west since late Victorian times and in the 1980s became popular across the west as a system of physical exercise.
In Indian traditions, yoga has a meditative and spiritual core. How much an individual engages in the physical benefits and how much in the spiritual aspects is a personal choice. The introductions to yoga offered as part of the Brighton Yoga Festival focus principally on exploring the the physical and mental benefits.
And if you’re new to yoga, you might appreciate this starter FAQ