Theravada Buddhism generally reads Sangha in its narrowest and most technical sense, the ordained community of monks and, historically, nuns, following the Vinaya's monastic discipline, a body legally and ritually distinct from the lay community that supports it materially in exchange for teaching and merit. Mahayana Buddhism, without abandoning the monastic sangha, widens the practical sense of community to include lay bodhisattvas pursuing the same ultimate goal as monastics, and some modern Mahayana movements, including lay Buddhist societies in Japan and Buddhist organizations built around lay teachers in the West, treat sangha as encompassing any community gathered around shared practice regardless of ordination status.
Vajrayana Buddhism adds a further layer sometimes called the three roots alongside, rather than replacing, the three jewels: the guru as the root of blessing, the yidam or meditational deity as the root of accomplishment, and the dharma protector as the root of activity, reflecting tantra's structure of transmission through a living teacher and a chosen deity form. Tibetan Buddhist teaching also distinguishes outer, inner and secret levels of refuge, with the outer refuge matching the ordinary three jewels formula shared across Buddhism, and the inner and secret levels adding the guru, deity and protector, and finally the practitioner's own awakened nature, in a structure reserved for practitioners who have received the corresponding tantric instruction.