Vinyasa means movement linked with breath. Postures are strung together in a short or longer flow. This style of yoga is often quite dynamic. The dynamic aspect of this style of yoga means that the mind has to stay focussed in the present to be able to keep up. This keeps you from drifting off, and helps you to achieve to stay present to what is rather than to what you think is going on, present in your body rather than being stuck in the head.