Nun

Nun, in strict Catholic canonical usage, denotes a woman religious belonging to an order of solemn vows, historically observing enclosure, cloister, a formal separation from the outside world governing a nun's movement and a monastery's own openness to visitors, and distinguishes such women from sisters, members of congregations of simple vows engaged in active ministries such as teaching, nursing or social work outside the monastery's walls; popular English usage collapses the distinction, calling any vowed Catholic religious woman a nun regardless of which canonical category she actually belongs to. Cloistered nuns, Carmelites, Poor Clares and Benedictine nuns among the most prominent orders, organize their life around communal prayer and contemplation, most orders supporting themselves through some combination of donations and enclosed work such as producing vestments, altar bread or other goods sold to support the community.

Degrees of enclosure vary by order and have been progressively relaxed since the Second Vatican Council, which encouraged religious communities to reconsider historical practices, including strict enclosure, in light of their founders' original charism and contemporary pastoral needs, though many contemplative communities of nuns have deliberately retained a substantial degree of separation from ordinary social life as central to their vocation's specific character rather than as an outdated restriction to be discarded.

Female monasticism developed alongside male monasticism from the early Christian centuries, with double monasteries, communities combining monks and nuns under a single abbess or abbot, common in the early medieval period in regions including Anglo-Saxon England and Merovingian Gaul before falling out of favor as later canon law increasingly required separate governance and stricter enclosure for women's communities specifically, a divergence reflecting the medieval church's generally more restrictive approach to women's public religious authority compared with men's. Enclosure requirements for nuns were significantly formalized by the Council of Trent in the sixteenth century, partly in response to concerns about the independence some women's communities had exercised, a formalization that shaped the strict cloister many people today associate with the word nun.

The modern distinction between nuns, of solemn vows and enclosure, and sisters, of simple vows and active ministry, though juridically clear in canon law, has become less significant in everyday usage and even within some communities' own self-description, particularly as many historically active congregations of sisters, teaching orders and nursing orders founded especially in the eighteenth and nineteenth centuries, vastly outnumber traditionally cloistered nuns in the contemporary Catholic Church, especially in mission territories and the developing world where such congregations have seen the most vocations growth in recent decades.