As Pope John Paul II noted:
“… What in people’s eyes can seem a waste is, for the individuals captivated in the depths of their heart by the beauty and goodness of the Lord, an obvious response of love, a joyful expression of gratitude for having been admitted in a
unique way to the knowledge of the Son and to a sharing in His divine mission in the world.." Consecrated Life, 104

"In the different forms of life inspired by the Spirit throughout history, consecrated persons discover that the more they stand at the foot of the cross of Christ, the more immediately and profoundly they experience the truth of God who is love." Consecrated Life, 24

A religious order is an organization of people who live in some way set apart from society in accordance with religious devotion. The members of such orders, termed religious as a group, are usually distinct from both the laity and the clergy. They are often termed monks, friars or brothers if male, and nuns or  sisters if female. Not all members of a religious order are clergy, and there may be lay members who have sworn an oath to the order or taken vows such as vows of poverty.

“A Carmelite is a soul who has gazed on the Crucified One … and has wanted to give herself as He did.” - Blessed Elizabeth of the Trinity Some orders practice literal isolation (cloistering) from the outside world; others remain engaged with the world in various ways, often teaching or serving in traditional roles, while maintaining their distinction in other ways (communal living, producing religious artwork and texts, designing and making vestments and writing  religious instruction books as examples). Some serve as canon lawyers or in diocesan administration.  Some religious are theologians and prolific writers. Some serve the poor and beg for  alms. All, however, may be distinguished by vows or disciplines they undertake as members of their orders.

Those sisters, brothers and priests who belong to an order are typically eferred to as “religious”. They live out in a special way what is termed the consecrated life.   They typically live in community. Living in community, they would eat together, pray together and celebrate Mass together.

"…Those who have been given the priceless gift of following the Lord Jesus more closely consider it obvious that he can and must be loved with an undivided heart, that one can devote to him one's whole life, and not merely certain actions or occasional moments or activities.…From such a life "poured out" without reserve there spreads a fragrance which fills the whole house. The house of God, the Church, today no less than in the past, is adorned and enriched by the presence of the consecrated life." Pope John Paul II, Consecrated Life, 104