All people of God are called to live a life of holiness.
Some may discern a vocation to a very public way of living out Christian discipleship. In the Roman Catholic Church, the Sacrament of Holy Orders is for when the church celebrates a man becoming a deacon, priest or bishop. These men are considered clergy of the church and are members of the Catholic hierarchy
Unmarried men may feel feel called to a vocation of priestly service and wish to seek ordination as a priest in the Roman Catholic Church. A priest is called to be a servant of the servants of God, celebrate the Sacraments, and lead the faithful to holiness.
Married or unmarried men (before ordination) may feel called to a life of ordained service to the church as permanent deacons. Deacons live a life of service to the church in a variety of ministries and activities. This service may also include service at the altar - assisting the priest in the celebration of the Holy Eucharist, Baptizing, and witnessing Marriages.
Other times, some individuals within our community may wish to enter Religious (or Consecrated) Life. These individuals join communities of other men or women and may feel called to take public vows of poverty, chastity and obedience (and, in some cases, other vows). Through prayer, joining a community of like-minded individuals, and through public vows, Religious Men and Women serve the church in all kinds of ministries. If the person is NOT a priest, they do NOT receive the Sacrament of Holy Orders in Religious (or Consecrated) life.
Members of religious orders (congregations) embrace the "charism" or special vision of the founders of those religious communities. For example, religious orders/congregations include the Dominicans (St. Dominic), the Benedictines (St. Benedict), the Franciscans (St. Francis) and the Jesuits (St. Ignatius), There are many religious orders and congregations in the Catholic Church who live out their congregation's charism and rule, usually live in community and serve in ministry in some way within the institutional church (or otherwise) in a variety of ways.
Some religious orders, in addition to having publicly vowed (professed) members, also admit lay people (single or married) to share in their charism by becoming privately vowed lay people (like, for instance, the Dominican Laity). These individuals take private vows (as opposed to the public vows that most nuns, sisters, brothers, monks and religious order priests take) and strive to live out the charism of their congregation.
Further, some lay men or women feel called to connect with the charism of a particular religious order/congregation without the need to take public or private vows. They can become "associates" (in some cases called oblates) connected with a particular religious congregation (e.g. Dominican Associates, Secular Franciscans, Benedictine Oblates, etc.). Check with the particular religious order/congregation you desire to connect with - to see how it works in their congregations, if you are a lay person (married or single) wishing to connect with a religious congregation in this way.
If you feel a call to a more formal expression of your Christian faith to live your life as a priest, deacon, religious sister or brother, nun or monk, or as a lay person associated with a religious order/congregation, please contact one of the parish priests.