I DO know I would hate to generalize. My experience of nuns and sisters is that they are eager to tell us what their role is.
"Religious" generally live lives as eschatological signs; they neither marry nor are given in marriage but are like the angles in heaven, sort of.
They follow more or less well, the evangelical counsel of poverty. At least usually the amount of personal possessions they may have is limited even when the community itself is prosperous. The success of Benedictine monasticism turned out too be a great temptation, again and again. If you work hard, live frugally, and "receive gifts from men" you can end up a little more well off than you had planned. That's one of the reasons for periodic monastic reforms.
I don't know much about Carmelite nuns. I do know that both the "Poor Clares" and the Dominican Second Order are enclosed nuns whose mission includes praying for the First Order Franciscans and Dominicans. This takes place in the context of a prayerful and simple life.
I would VENTURE to say that for nuns as for male "religious" the idea is to approach as much as possible a 24/7 dedication of oneslef to living in the Love of God, with as few distractions as possible. However orders have "charisms", for instance to serve to poor, abandoned, and sick. Other charisms include preaching, teaching (and study), and other good works.
Though it's about men and not women, I think "Into the Great Silence", available on Netflix , is a wonderful film about structured communal lives given to solitary contemplation.
Luke describes Mary, more than once, as pondering in her heart about various aspects of her Son. Consequently she is a kind of a hero to contemplatives.
Is this the kind of answer you were wanting?
N.B. I may be away from my confuser for the rest of the day.
Yes, that’s what I wanted. Thank you!