Vajrayāna Buddhism, also known as Tantric Buddhism, Tantrayana, Mantrayana, Mantranaya, Esoteric Buddhism, Diamond Vehicle (Chinese: 金剛乘, jingangcheng, Japanese: 金剛乗, kongōjō) although these terms are not always regarded as equivalent, is an extension of Mahayana Buddhism consisting of differences in the adoption of additional techniques (upaya, or 'skillful means') rather than in philosophy. Thus, before terms such as Vajrayāna or Tantrayāna came into use, scholar-monks such as Buddhaguhya (fl. mid-8th CE) state that Mahāyāna is subdivided into two categories: pāramitā-yana (the "Perfection Method") and mantra-yana (the "Mantra Method"). Some of these upāya are esoteric practices which must be initiated and transmitted only through a skilled spiritual teacher. The Vajrayana is often viewed as the third major 'vehicle' (Yana) of Buddhism, alongside the Theravada and Mahayana.
Tantra is that Asian body of beliefs and practices which, working from the principle that the universe we experience is nothing other than the concrete manifestation of the divine energy of the Godhead that creates and maintains that universe, seeks to ritually appropriate and channel that energy, within the human microcosm, in creative and emancipatory ways.
Tsongkhapa (Tibetan: ཙོང་ཁ་པ་, Wylie: Tsong-kha-pa) (1357 – 1419), whose name means "The Man from Onion Valley", was a famous teacher of Tibetan Buddhism whose activities led later to the formation of the Geluk (Dge-lugs) school. He is also known by his ordained name Lobsang Drakpa (Blo-bzang Grags-pa) or simply as "Je Rinpoche" (Rje Rin-po-che).
Tsongkhapa heard Buddha's Teachings from masters of all Tibetan Buddhist traditions, and received lineages transmitted in the major schools.
His main source of inspiration was the Kadampa (Bka'-gdams-pa) tradition, the legacy of Atiśa. Based on Tsongkhapa's teaching, the two distinguishing characteristics of the Gelug tradition are: