These three common terms refer to different specific religious roles or functions, any or all of which could be exemplified in a single person. They are often used synonymously, but there are important differences. A sadhu is “a person of unerring trajectory” or “one who has achieved a goal” by means of a regime of spiritual practices and disciplines called collectively sadhana. These methods encompass a whole range of external rituals, including fasting and other austerities, and forms of meditation, and often vary from one denomination or sect to another. Sadhus pursue a highly ascetic lifestyle, live on charitable donations, and are often entirely unconnected with specific social or religious institutions—apart from the fact that sadhu-hood has become virtually an institution in itself. Some sadhus are also sannyasis, renunciants officially initiated into this spiritual status by a guru. Individuals may formally enter into the state of sannyasa for various reasons according to tradition: a spontaneous quest for spiritual liberation; a quest resulting from more deliberate immersion in religious studies; withdrawal as a way to cope with great loss or sadness; or the realization that one’s death is imminent. Formal initiation, also conferred on women in some orders, includes vows of poverty, chastity, and obedience for those who belong to monastic communities. Sadhus and sannyasis may also engage in the disciplines of raja and hatha yoga, but a yogi is not necessarily either a sadhu or a sannyasi.