Psalms is an Old Testament book of the Bible that contains 150 poems (or songs) called psalms, one of which (Psalm 119) is exceptionally long. Each psalm is intended to be sung (or performed) individually as part of prayer or worship. Psalms can be categorized by topic including: hymns of praise, hymns of thanksgiving, lamentations, hymns of belief and wisdom, hymns of history, rage, and liturgical psalms.