A breviary is a liturgical book

Liturgical book

A liturgical book is a book published by the authority of a church, that contains the text and directions for the liturgy of its official religious services.-Roman Catholic:...

 of the Latin liturgical rites

Latin liturgical rites

Latin liturgical rites used within that area of the Catholic Church where the Latin language once dominated were for many centuries no less numerous than the liturgical rites of the Eastern autonomous particular Churches. Their number is now much reduced...

 of the Catholic Church containing the public or canonical prayer

Prayer

Prayer is a form of religious practice that seeks to activate a volitional rapport to a deity through deliberate practice. Prayer may be either individual or communal and take place in public or in private. It may involve the use of words or song. When language is used, prayer may take the form of...

s, hymn

Hymn

A hymn is a type of song, usually religious, specifically written for the purpose of praise, adoration or prayer, and typically addressed to a deity or deities, or to a prominent figure or personification...

s, the Psalms

Psalms

The Book of Psalms , commonly referred to simply as Psalms, is a book of the Hebrew Bible and the Christian Bible...

, readings, and notations for everyday use, especially by bishops, priests, and deacons in the Divine Office (i.e., at the canonical hours

Canonical hours

Canonical hours are divisions of time which serve as increments between the prescribed prayers of the daily round. A Book of Hours contains such a set of prayers....

 or Liturgy of the Hours

Liturgy of the hours

The Liturgy of the Hours or Divine Office is the official set of daily prayers prescribed by the Catholic Church to be recited at the canonical hours by the clergy, religious orders, and laity. The Liturgy of the Hours consists primarily of psalms supplemented by hymns and readings...

, the Christians' daily prayer). The word can also refer to a collection of Christian orders of prayers and readings, such as contained in Anglican or Lutheran resources.