Vajrayana, (Sanskrit: “Thunderbolt Vehicle” or “Diamond Vehicle”) form of Tantric Buddhism that developed in India and neighboring countries, notably Tibet. Vajrayana, in the history of Buddhism, marks the transition from Mahayana speculative thought to the enactment of Buddhist ideas in individual life. (source: Britannica.com)
Khenpo Tenzin Norgay taught about this in 2005 at KPC.