A Psalter (also known as the Psalms of David) is a volume containing the book of Psalms and often other devotional material.

In the early middle ages, Psalters were amongst the most popular types of illuminated manuscripts, rivaled only by the Gospel Books.

Medieval Psalters often included a calendar, a litany of saints, canticles from the Old and New Testaments, as well as other devotional texts.

Many Psalters were lavishly illuminated with full-page miniatures as well as decorated initials.

In the Eastern Orthodox Church the Psalter is divided into 20 kathismata, for reading at Vespers and Matins. Kathisma means sitting, since the people normally sit during the reading of the psalms.

Book of Hours:

A book of hours is the most common type of surviving medieval illuminated manuscript. Each book of hours is unique in one way or another, but all contain a collection of texts, prayers and psalms...

The Latin word hours is horae, the English term primer is usually only used to refer to books of hours written in English. Books of hours were usually written in Latin, although some are entirely or partially in vernacular European languages. Several hundred thousand books of hours have survived to the present day, scattered across libraries and private collections throughout the world.

The book of hours can be thought of as an abbreviated breviary, the book containing the Divine Office recited in monasteries. The books of hours were composed for lay people who wished to incorporate elements of monasticism into their devotional life.

One of the most famous books of hours, and one of the most richly illuminated medieval manuscripts, is the Très Riches Heures painted sometime between 1412 and 1416 inFrance for John, Duke of Berry.