Little Monastics in Buddhism
A male samanera or female samaneri -- literally a "little recluse" (samana, shramana, shaman, a renunciate or wandering ascetic) -- is a Buddhist novice monk or nun in training and on probation.
Tibetan Buddhist boys
The recluse ascetics (shramanas) are distinct from the brahmin priests (brahmanas), who were the dominant spiritual caste in India. The history of recluses goes as far back in time as humanity does. But the Buddha revolutionized their significance by organizing one group of them.
There have always been spiritual recluses, hermits, wanderers, shamans, and independent practitioners by nature (guided by the impulse of past lives to continue their spiritual quest free of institutional constraints).
Korean novice having his head shaved ceremonially to enter Mahayana Sangha.
At the time of the Buddha, recluses already existed. In fact, Siddhartha was inspired by the sight of one to again take up this kind of life. Why was he so moved?
The Jatakas (Buddhist Birth Stories) explain: They recount many previous lives of the Bodhisatta striving as a recluse and even as a brahmin well versed in the Vedas. The Jains were another organized contemporary shramanic school, the only other one to survive alongside Buddhism.
But the success of these two schools inspired Hindu yogis and sannyasis (followers of Shiva, Shavites, and Vishnu, Vaishnavites and even Mystic Muslim Sufi fakirs) to wander as well. It led to a Sannyasi Rebellion. Wandering was in fact a key component of early Buddhism, which led to detachment, contentment, and open mindedness.
Although fully ordained monastics were encouraged to meditate, wander freely, reside in the forest, fashion robes from discarded cloth, and live on alms gathered in one of only five possessions permitted by the rules of monastic discipline (Vinaya) in the Sangha, trainees were closely affiliated with a preceptor for their training first.
Generally, one must be at least seven years old to become a novice or be over 60, in which case one entering will remain a novice. Otherwise, once one reaches the age of 20, it is customary to take the higher ordination (upasampada) and become a fully ordained bhikkhu (monk) or bhikkhuni (nun). One goes from ten precepts to reciting the patimokkha (Sanskrit, prati-moksha, the way to personal liberation) or list of 227 plus disciplinary rules.