The third major branch, alongside Hinayana and Mahayana, according to Tibetan Buddhism's view of itself. Vajrayāna is also known as Tantric Buddhism, Tantrayāna, Mantrayāna, Secret Mantra, Esoteric Buddhism and the Diamond Way or Thunderbolt Way. Vajrayāna is a complex and multifaceted system of Buddhist thought and practice which evolved over several centuries.
According to Vajrayāna scriptures, the term Vajrayāna refers to one of three vehicles or routes to enlightenment, the other two being the Śrāvakayāna (also known as the Hīnayāna) and Mahāyāna.
Founded by Indian Mahāsiddhas, Vajrayāna subscribes to Buddhist tantric literature.
Example via www.ramdass.org: Lama Tsultrim Allione & the Divine Feminine