The guru is of crucial importance in Buddhism, as it is believed a true, authentic teacher is needed to help the devotee find the right path. Dakinis are female deities, often serving as consorts, who are necessary for certain meditations. Deities with fierce image function as protectors and defenders in the outer world, and as transmuters of destructive impulses in the inner world. Yab-yum is a Tibetan term meaning literally Father-Mother. They represent wisdom and compassion (skillful means) locked in embrace.