The Rosary is the recitation of five decades of the Our Father, ten Hail Mary's, and a Glory Be. The person mediates on the saving mysteries of our Lord's life and the Blessed Mother. The mysteries include: Joyful mystery,Glorious mystery, Sorrowful mystery, and Luminous mystery.
The Rosary beads are used to keep track of prayers being recited. The Rosary reminds us of what Jesus lived through and did for us. By praying the Rosary, people obtain a deeper appreciation of these events in His life.
The origin of the Rosary is not clear. During the earliest days of the Church, Catholics used prayer beads and the repetitive prayers. There is evidence that beads were used to assist prayers in the Middle Ages.
During the fifteenth century, the Rosary structure formed. Fifty Hail Mary's were recited and were linked with verses of psalms. The prayer was called rosarim meaning rose garden. Later, the name became the Rosary.
Saint Dominick is the person that designed the structure of the Rosary. He was moved by a vision of our Blessed Mother. The Rosary became popular in the 1500's. There were many wars, and people turned to the Rosary for comfort. On October 7, 1572, Pope St. Pius V established the Feast of the Holy Rosary.
The Rosary prayer brings human solidarity. It reflects the intent of Mary and Jesus. This prayer can be said by anyone in the world.
Extracted from catholicism.about.com