Definition of Y.A.N.A.
Yāna (Sanskrit and Pāli: “vehicle”) refers to a mode or method of spiritual practice. In Buddhism, yāna often expands the metaphor of the spiritual path with the idea of various vehicles that convey a person along that path. (Source: Answers.com)
As for Yana Yoga, it is simply the acronym bringing together a vehicle for your personal journey.
