Vajrayana (Devanagari: वज्रयान; Oriya: ବଜ୍ରଯାନ, Tibetan: རྡོ་རྗེ་ཐེག་པ་, rdo rje theg pa; Mongolian: Очирт хөлгөн, Ochirt Hölgön, Chinese: 密宗, mì zōng) is also known as Tantric Buddhism, Tantrayāna, Mantrayāna, Secret Mantra, Esoteric Buddhism and the Diamond Vehicle. Vajrayana is a complex and multifaceted system of Buddhist thought and practice which evolved over several centuries. According to Vajrayana scriptures Vajrayana refers to one of three vehicles or routes to enlightenment, the other two being the Theravada and Mahayana. Its main scriptures are called TantrasA d. istinctive feature of Vajrayana Buddhism is the use of rituals, which are Skillful Means (Upaya). They are being used as a substitute or alternative for the earlier abstract meditations.