The word rosary comes from Latin and means a garland of roses, the rose being one of the flowers used to symbolize the Virgin Mary. If you were to ask what object is most emblematic of Catholics, people would probably say, “The rosary, of course.” We’re familiar with the images: the silently moving lips of the old woman fingering her beads; the over-sized rosary hanging from the waist of the wimpled nun; more recently, the merely decorative rosary hanging from the rear view mirror.
After Vatican II the rosary fell into relative disuse. The same is true for Marian devotions as a whole. But in recent years the rosary has made a comeback, and not just among Catholics. Many Protestants now say the rosary, recognizing it as a truly biblical form of prayer—after all, the prayers that comprise it come mainly from the Bible.
The rosary is a devotion in honor of the Virgin Mary. It consists of a set number of specific prayers. First are the introductory prayers: one Apostles’ Creed, one Our Father, three Hail Marys, one Glory Be. Between the introductory prayers and the concluding prayer (The Hail Holy Queen) is the meat of the rosary: the decades. Each decade—there are twenty in a full rosary (which takes about forty-five minutes to say)—is composed of ten Hail Marys. Each decade is bracketed between an Our Father and a Glory Be, so each decade actually has twelve prayers. Both Catholics and non-Catholics, as they learn more about the rosary and make more frequent use of it, come to see how its meditations bring to mind the sweet fragrance not only of the Mother of God, but of Christ himself. catholic.com
The Divine Mercy Chaplet:
Prayed on ordinary rosary beads, The Chaplet of The Divine Mercy is an intercessory prayer that extends the offering of the Eucharist, so it is especially appropriate to use it after having received Holy Communion at Holy Mass. It may be said at any time, but our Lord specifically told St. Faustina to recite it during the nine days before the Feast of Mercy (the first Sunday after Easter). He then added: “By this Novena, [of Chaplets] I will grant every possible grace to souls.” (796)
It is likewise appropriate to pray the Chaplet during the “Hour of Great Mercy” — three o’clock each afternoon (recalling the time of Christ’s death on the cross). In His revelations to St. Faustina, Our Lord asked for a special remembrance of His Passion at that hour. thedivinemercy.org