Read The Concise Oxford Dictionary of World Religions Online
Authors: John Bowker
(i) Kriy
tantra, describing relatively obvious and accessible rituals;
(ii) Cary
tantra, more advanced ‘outer ritual’ and the beginnings of ‘inner yoga’;
(iii) Yogatantra, the workings of ‘inner yoga’ in meditation and trance;
(iv) Anuttarayogatantra, esoteric rituals, often concerned with the workings of sexual symbolism, accessible only to the initiated