Monasticism (from Greek μοναχός, monachos, derived from μόνος, monos, "alone") or monkhood is a religious way of life that involves renouncing worldly pursuits to fully devote one's self to spiritual work. Monastic life plays an important role in many Christian churches, especially in the Catholic and Orthodox tradition. Similar forms of religious life also exist in other faiths, most notably in Buddhism, but also Hinduism and Jainism, though the expressions differ considerably.
Males pursuing a monastic life are generally called monks while female monastics are called nuns. The way of addressing monastics differs between the Christian traditions. For a general rule, in Roman Catholicism, monks and nuns are called brother or sister, while in Orthodox Christianity, they are called father or mother. This is not an absolute rule as their address varies depending on their rank and monastic tradition.
The Sangha or community of ordained Buddhist bhikkhus (similar to monks) and original bhikkhunis (similar to nuns) was founded by Gautama Buddha during his lifetime over 2500 years ago. This communal monastic lifestyle grew out of the lifestyle of earlier sects of wandering ascetics, some of whom the Buddha had studied under. It was initially fairly eremitic or reclusive in nature. Bhikkhus and bhikkunis were expected to live with a minimum of possessions, which were to be voluntarily provided by the lay community. Lay followers also provided the daily food that bhikkhus required, and provided shelter for bhikkhus when they were needed.
After the Parinibbana (Final Passing) of the Buddha, the Buddhist monastic order developed into a primarily cenobitic or communal movement. The practice of living communally during the rainy vassa season, prescribed by the Buddha, gradually grew to encompass a settled monastic life centered on life in a community of practitioners. Most of the modern disciplinary rules followed by bhikkhus and bhikkhunis — as encoded in the Patimokkha — relate to such an existence, prescribing in great detail proper methods for living and relating in a community of bhikkhus or bhikkhunis. The number of rules observed varies with the order; Theravada bhikkhus follow around 227 rules. There are a larger number of rules specified for bhikkhunis (nuns).
The Buddhist monastic order consists of the male bhikkhu assembly and the female bhikkhuni assembly. Initially consisting only of males, it grew to include females after the Buddha's stepmother, Mahaprajapati, asked for and received permission to live as an ordained practitioner.
Bhikkhus and bhikkhunis are expected to fulfill a variety of roles in the Buddhist community. First and foremost, they are expected to preserve the doctrine and discipline now known as Buddhism. They are also expected to provide a living example for the laity, and to serve as a "field of merit" for lay followers—providing laymen and women with the opportunity to earn merit by giving gifts and support to the bhikkhus. In return for the support of the laity, bhikkhus and bhikkhunis are expected to live an austere life focused on the study of Buddhist doctrine, the practice of meditation, and the observance of good moral character.
A bhikkhu (the term in the Pali language) or Bhikshu (in Sanskrit), first ordains as a Samanera (novice). Novices often ordain at a young age, but generally no younger than eight. Samaneras live according to the Ten Precepts, but are not responsible for living by the full set of monastic rules. Higher ordination, conferring the status of a full Bhikkhu, is given only to men who are aged 20 or older. Bhikkhunis follow a similar progression, but are required to live as Samaneras for longer periods of time- typically five years.
The disciplinary regulations for bhikkhus and bhikkhunis are intended to create a life that is simple and focused, rather than one of deprivation or severe asceticism. However, celibacy is a fundamental part of this form of monastic discipline.