Monastic life used to be divided into two 'classes'. The choir nuns were fully enclosed and sung the Divine Office in choir. Lay nuns could go outside the enclosure for whatever purpose (authorized by their superior) and were often engaged in the manual and menial tasks within the Order. They were fully relgious as the choir nuns.
I am unsure if this division may have existed in the contemplative male orders also, it may well have.
Often the lay sisters were not of the educational standard of the choir nuns. I am unsure of what applies in all orders nowadays, certainly some contemplative orders have abandoned the distinction.
In most of the older contemplative
orders the choir nuns
are bound to rthe whole Divine Office
in choir. In only a very few of the English
convents, e.g. Cistercians
, and Poor Clares
, do the nuns
rise in the night for Matins
; in the others these Offices are generally said in the evening "by anticipation". In some there are other additional offices recited daily; thus the Cistercians
and the Poor Clares
say the Office of Our Lady and that of the Dead every day, and the Brigittines
say the latter thrice in the week, as well as an Office of the Holy Ghost
. Almost all the active orders, both enclosed and unenclosed, use the Office of Our Lady, but some, like the Sisters of Charity, are not bound to the recitation of any Office at all.
In most orders the nuns
are divided into choir sisters and lay sisters. The latter are usually employed in the household duties
and other manual work. They take the usual vows
and are as truly religious as the choir nuns
, but they are not bound to the choir Office, though they often attend the choir at the time of Office and recite certain prayers
in the vernacular. There is always a distinction between their habit and that of the choir nuns
, sometimes very slight and sometimes strongly marked. In some orders where the choir sisters are enclosed the lay sisters are not; but in others they are as strictly enclosed as the choir nuns
. Several orders have, by their rule, no lay sisters, among them being the Sisters of Notre Dame, the Sisters of Charity, the Sisters of Bon Secours, the Little Sisters of the Poor
, and the Poor Servants of the Mother of God