“From ancient times the Church has had the custom of celebrating each day the liturgy of the hours. In this way the Church fulfills the Lord’s precept to pray without ceasing, at once offering its praise to God the Father and interceding for the salvation of the world.” — Office of the Sacred Congregation for Divine Worship.
The Divine Office or the “liturgy of the hours” is the official prayer of the Church and is prayed at certain hours throughout the day. It consists mainly of psalms, hymns, and readings. Priests and many religious orders are obligated to say the Divine office daily. Other religious orders only require some of hours of prayer to be said, but if you visit a monastery, you will find that they typically pray the complete Liturgy of the Hours. Lay people all over the world also say the Divine Office. To find out more about this sacred prayer of the church go to Divine Office.