Monasticism (from Greek μοναχός, monachos, derived from Greek monos, alone) is a religious way of life characterized by the practice of renouncing worldly pursuits to fully devote one's self to spiritual work. The origin of the word is from Ancient Greek, and the idea originally related to Buddhist monks in 550 B.C.

In the Catholic, Orthodox, and Coptic Christian traditions, males pursuing a monastic life are generally called monks while female monastics are called nuns. Both monks and nuns are considered monastics. 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. Some other religions also include monastic elements, most notably Buddhism, but also Hinduism and Jainism, though the expressions differ considerably.

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.