The Rosary (; Latin: rosarium, in the sense of "crown of roses" or "garland of roses"), formally known as the Psalter of Jesus and Mary (Latin: Psalterium Jesu et Mariae), also known as the Dominican Rosary (as distinct from other forms of rosary such as the Franciscan Crown, Bridgettine Rosary, Rosary of the Holy Wounds, etc.), refers to a set of prayers used primarily in the Catholic Church, and to the physical string of knots or beads used to count the component prayers. When referring to the prayer, the word is usually capitalized ("the Rosary", as is customary for other names of prayers, such as "the Lord's Prayer", and "the Hail Mary"); when referring to the prayer beads as an object, it is written with a lower-case initial letter (e.g. "a rosary bead").
The prayers that compose the Rosary are arranged in sets of ten Hail Marys, called "decades". Each decade is preceded by one Lord's Prayer ("Our Father"), and traditionally followed by one Glory Be. Some Catholics also recite the "O my Jesus" prayer after the Glory Be; it is the best-known of the seven Fátima prayers that appeared in the early 20th century. Rosary prayer beads are an aid for saying these prayers in their proper sequence.
