A sadhu has formally renounced ordinary household life, family ties and personal property to pursue moksha, liberation, through ascetic practice, pilgrimage and meditation, a life stage many Hindu traditions treat as the culmination of the four-stage ashrama scheme, though sadhus themselves span considerable diversity in their specific practices, philosophical affiliations and degree of asceticism, from wandering mendicants entirely dependent on alms to sadhus affiliated with organized monastic orders and akharas maintaining fixed residences at particular ashrams or temples. Initiation as a sadhu, diksha, is conferred by an existing guru and typically involves formal renunciation rites, including, in some traditions, symbolic rituals treating the initiate's prior worldly identity as having died, a practice paralleling similar rites of symbolic death and rebirth found in the closely related swami initiation within the Dashanami order.
Sadhus are broadly divided into Shaiva sadhus, devoted to Shiva and often organized into akharas historically associated with martial as well as religious training, and Vaishnava sadhus, devoted to Vishnu and his avatars, each tradition maintaining its own distinct practices, insignia, such as the specific pattern of ash or sandalwood paste markings worn on the forehead and body, and organizational structures, so that identifying a sadhu's specific sectarian affiliation is often possible simply from these visible markers.