Three yanas of powerful transformative methods

Three Yanas of Powerful Transformative Methods (Tib. dbang sgyur thabs kyi theg pa gsum) - These are the three inner classes of tantra: the yana of mahayoga, the yana of anuyoga and the yana of atiyoga.

You might wonder why are these are called ‘vehicles of powerful transformative methods.’ It is because they include powerful methods for transforming all phenomena into great purity and equalness.