A prayer book is a book containing prayers and perhaps devotional readings, for private or communal use, or in some cases, outlining the liturgy of religious services. Books containing mainly orders of religious services, or readings for them are termed "service books" or "liturgical books", and are thus not prayer-books in the strictest sense, but the term is often used very loosely. A religion's scriptures might also be considered prayer books as well.
See main article: article and Siddur.
In Judaism, the Siddur is a prayer book "containing the three daily prayers; also the prayers for Shabbat, Rosh-Chodesh and the festivals."[1]
See main article: article, Liturgical book and List of Christian devotional literature.
Breviaries are prayer books used in many Christian denominations by believers to pray at fixed prayer times the canonical hours seven times a day, a practice that has its roots in 119:164 KJV.[2]
Throughout the year, and especially during certain seasons of the Christian liturgical kalendar such as Advent and Lent, many Christians pray a daily devotional, which contains a prayer for each day along with a reflection on a passage from the Christian Bible.
The following are among the many books to which the term may loosely refer in various churches, although in strict usage a prayer book is likely to mean a miscellaneous book of prayers as opposed to the standard service books as listed in the last group below:
General
Breviaries
The canonical prayer book in Mandaeism is the Qulasta.