Lay brother is a largely extinct term referring to religious brothers, particularly in the Catholic Church, who focused upon manual service and secular matters, and were distinguished from choir monks or friars in that they did not pray in choir, and from clerics, in that they were not in possession of (or preparing for) holy orders.     
In female religious institutes, the equivalent role is the lay sister. Lay brothers were originally created to allow those who were skilled in particular crafts or did not have the required education to study for holy orders to participate in and contribute to the life of a religious order.
“In early Western monasticism, there was no distinction between lay and choir religious. The majority of St. Benedict's monks were not clerics, and all performed manual labour, the word conversi being used only to designate those who had received the habit late in life, to distinguish them from the oblati and nutriti. But, by the beginning of the 11th century, the time devoted to study had greatly increased, thus a larger proportion of the monks were in Holy Orders, even though great numbers of illiterate persons had embraced the religious life. At the same time, it was found necessary to regulate the position of the famuli, the hired servants of the monastery, and to include some of these in the monastic family. So in Italy the lay brothers were instituted; and we find similar attempts at organization at the Abbey of St. Benignus at Dijon, under William of Dijon (d. 1031) and Richard of Verdun (d. 1046), while at Hirschau Abbey, Abbot William (d. 1091) gave a special rule to the fratres barbati and exteriores.” 
“At Cluny Abbey the manual work was relegated mostly to paid servants, but the Carthusians, the Cistercians, the Order of Grandmont, and most subsequent religious orders possessed lay Brothers, to whom they committed their secular cares. In particular, at Grandmont, the complete control of the order's property by the lay brothers led to serious disturbances, and finally to the ruin of the order; whereas the wiser regulations of the Cistercians provided against this danger and formed the model for the later orders. In England, the Benedictines made but slight use of lay brothers, finding the service of paid attendants more convenient.” Nonetheless, they are “mentioned in the customaries of the Abbey of St. Augustine at Canterbury and the Abbey of St. Peter at Westminster.” 
In 1965, the Second Vatican Council issued the document Perfectae Caritatis , which called upon all religious institutes to re-examine and renew their charism. As part of the subsequent reforms and experimentation, many of the distinctions between lay and choir religious in terms of dress and spiritual regimen were abolished or mitigated. In many religious institutes, lay and choir religious wear the same habit.
Lay brothers were found in many religious orders. Drawn from the working classes, they were pious and hardworking people, who though unable to achieve the education needed to receive holy orders, were still drawn to religious life and were able to contribute to the order through their skills. Some were skilled in artistic handicrafts, others functioned as administrators of the orders' material assets. In particular, the lay brothers of the Cistercians were skilled in agriculture, and have been credited for the tilling of fertile farmland. 
Lay brothers were sometimes distinguished from their brethren by some difference in their habit: for instance, the Cistercian lay brother previously wore a brown tunic, instead of white, with the black scapular; in choir they wore a large cloak, instead of a cowl; the Vallombrosan lay brothers wore a cap instead of a hood, and their habit was shorter; the English Benedictine lay brothers wore a hood of a different shape from that of the choir monks, and no cowl; a Dominican lay brother would wear a black, instead of a white, scapular. In some orders they were required to recite daily the Little Office of the Blessed Virgin Mary, but usually their labor in the fields (and hence away from the church) prevented them from participating in the Liturgy of the Hours. Lay brothers would instead pray Paters, Aves, and Glorias. 
Lay sisters were found in most of the orders of women, and their origin, like that of the lay brothers, is to be found in the necessity of providing the choir nuns with more time for the Office and study, as well as creating the opportunity for the illiterate to join the religious life. They, too, wore a habit different from those of the choir sisters, and their required daily prayers consisted of prayers such as the Little Office or a certain number of Paters. 
The system of lay sisters seem to have appeared earlier than that of lay brothers, being first recorded in a ninth century hagiography of Saint Denis. In the early medieval period, there was also mention of lay brothers attached to convents of women and of lay sisters attached to monasteries. In both configurations, the two sexes were strictly kept separate, housed in distinct buildings. This arrangement, however, has since been long abolished. 
Abbot is an ecclesiastical title given to the male head of a monastery in various Western religious traditions, including Christianity. The office may also be given as an honorary title to a clergyman who is not the head of a monastery. The female equivalent is abbess.
A monastery is a building or complex of buildings comprising the domestic quarters and workplaces of monastics, monks or nuns, whether living in communities or alone (hermits). A monastery generally includes a place reserved for prayer which may be a chapel, church, or temple, and may also serve as an oratory, or in the case of communities anything from a single building housing only one senior and two or three junior monks or nuns, to vast complexes and estates housing tens or hundreds. A monastery complex typically comprises a number of buildings which include a church, dormitory, cloister, refectory, library, balneary and infirmary, and outlying granges. Depending on the location, the monastic order and the occupation of its inhabitants, the complex may also include a wide range of buildings that facilitate self-sufficiency and service to the community. These may include a hospice, a school, and a range of agricultural and manufacturing buildings such as a barn, a forge, or a brewery.
The Cistercians, officially the Order of Cistercians, are a Catholic religious order of monks and nuns that branched off from the Benedictines and follow the Rule of Saint Benedict, as well as the contributions of the highly-influential Bernard of Clairvaux, known as the Latin Rule. They are also known as Bernardines, after Saint Bernard himself, or as White Monks, in reference to the colour of the "cuculla" or cowl worn by the Cistercians over their habits, as opposed to the black cowl worn by Benedictines.
A religious order is a lineage of communities and organizations of people who live in some way set apart from society in accordance with their specific religious devotion, usually characterized by the principles of its founder's religious practice. It is usually composed of laypeople and, in some orders, clergy. Such orders exist in many of the world's religions.
Augustinians are members of Christian religious orders that follow the Rule of Saint Augustine, written in about 400 AD by Augustine of Hippo. There are two distinct types of Augustinians in Catholic religious orders dating back to the 12th–13th centuries:
A monk is a person who practices religious asceticism by monastic living, either alone or with any number of other monks. A monk may be a person who decides to dedicate their life to serving other people and serving God, or to be an ascetic who voluntarily chooses to leave mainstream society and live their life in prayer and contemplation. The concept is ancient and can be seen in many religions and in philosophy.
The scapular is a Western Christian garment suspended from the shoulders. There are two types of scapulars, the monastic and devotional scapular, although both forms may simply be referred to as "scapular". As an object of popular piety, it serves to remind the wearers of their commitment to live a Christian life.
The Gilbertine Order of Canons Regular was founded around 1130 by Saint Gilbert in Sempringham, Lincolnshire, where Gilbert was the parish priest. It was the only completely English religious order and came to an end in the 16th century at the time of the Dissolution of the Monasteries. Modest Gilbertine revivals have taken place in the late 20th and early 21st centuries on three continents.
In the Catholic Church, a religious order is a community of consecrated life with members that profess solemn vows. They are classed as a type of religious institute.
Grandmontines were the monks of the Order of Grandmont, a religious order founded by Saint Stephen of Thiers, towards the end of the 11th century. The order was named after its motherhouse, Grandmont Abbey in the eponymous village, now part of the commune of Saint-Sylvestre, in the department of Haute-Vienne, in Limousin, France. They were also known as the Boni Homines or Bonshommes.
A cowl is an item of clothing consisting of a long, hooded garment with wide sleeves, often worn by monks.
In Christianity, an oblate is a person who is specifically dedicated to God and to God's service.
Canons regular are priests who live in community under a rule and are generally organised into religious orders, differing from both secular canons and other forms of religious life, such as clerics regular, designated by a partly similar terminology.
A religious is, in the terminology of many Western Christian denominations, such as the Catholic Church, Lutheran Churches, and Anglican Communion, what in common language one would call a "monk" or "nun". A religious may also be a priest if he has undergone ordination, but in general he is not.
The Cluniac Reforms were a series of changes within medieval monasticism of the Western Church focused on restoring the traditional monastic life, encouraging art, and caring for the poor. The movement began within the Benedictine order at Cluny Abbey, founded in 910 by William I, Duke of Aquitaine (875–918). The reforms were largely carried out by Saint Odo and spread throughout France, into England, and through much of Italy and Spain.
A religious habit is a distinctive set of religious clothing worn by members of a religious order. Traditionally some plain garb recognizable as a religious habit has also been worn by those leading the religious eremitic and anchoritic life, although in their case without conformity to a particular uniform style.
The Valliscaulian Order was a religious order of the Catholic Church. It was named after Vallis Caulium or Val-des-Choux, its first monastery, located in Burgundy. The order was founded at the end of the twelfth century and lasted until its absorption by the Cistercians in the eighteenth century.
Cistercian nuns are female members of the Cistercian Order, a religious order belonging to the Roman Catholic branch of the Catholic Church.
A religious brother is a member of a Christian religious institute or religious order who commits himself to following Christ in consecrated life of the Church, usually by the vows of poverty, chastity and obedience. He is a layman, in the sense of not being ordained as a deacon or priest, and usually lives in a religious community and works in a ministry appropriate to his capabilities.
Anglican Cistercians are members of the Anglican Communion who live a common life together according to the Cistercian tradition. This tradition is usually dated to 1098 in origin. The term Cistercian is derived from Cistercium, the Latin name for the village of Cîteaux, near Dijon in eastern France. It was in this village that a group of Benedictine monks from the monastery of Molesme founded Cîteaux Abbey in 1098, with the goal of following more closely the Rule of Saint Benedict. Monks following this rule are known as Benedictine, and were at that time the dominant force in Christian monasticism. The monks of Cîteaux Abbey effectively founded a new order, but one that remains closely associated with the Benedictine Order. As a mark of their distinctive charism and rule, Cistercian monks have long worn white habits to distinguish themselves from Benedictine monks who wear black habits. Within Anglicanism there has historically been less interest in the Cistercian Order than certain other monastic Rules, although Cistercian life has been represented continuously in the Church of England since at least 1966.