Yang means movement, stretching muscles and physical action. It will always be a small part of a Yin-Yang yoga lesson. After the Yang we'll slowly move to the Yin. Yin yoga is a counterpart to the rushed Western lifestyle. A form of yoga with emphasis on calm and gentleness.
Boot Camp is an open-air lesson alternating fitness exercises such as running or walking with exercises focussing on strength. These exercises are done with your own body weight instead of equipment, so most of the time several muscle groups are trained at the same time, challenging not only your muscles, but also your coordination.