>>596896
Most has been said already ITT, even the rule of Theotokos has been mentioned (although it's wrong to call it the Byzantine Rosary, it's simply just another devotion to the Holy Mother that also contemplates the life of Christ), but I'd still like to add one or the other thing.
First of all, there is a distinction between the prayer beads which you call rosary and the Rosary, which is the prayer rule. The former is just (as mentioned before) a mere tool to help you not lose track of where you are in the prayer rule at the moment.
Secondly, the Rosary - and many prots will object a la "muh vain repititions" - has different layers of prayer and meaning, to use a bit of a modern expression. First of all, you have vocal prayer, that is: the prayers of the rule themselves. If you're a beginner, you learn these first and remember their succession etc.. Then you have the mysteries of the chaplets. These represent all major "things" in Christ's life: from the annunciation of Mary and her immaculate conception to His Crucifixion and the Coronation of Mary. We contemplate these - or try to (although in the beginning getting the prayer rule straight should be your first aim). That is the actual core of the Rosary, which is why it is a Christ-centered prayer rule where we look at the life of Christ through the eyes of our blessed mother. The vocal prayer is, despite being prayers to glorify God and to ask Mary to pray for us, to a large extend to keep your focus (i.e. prevent your thoughts from drifting).
Last but not least, the Rosary is our main weapon against evil and temptation. To focus on the life of Christ and to ask Mary for prayer is to realize that the devil has no power over us if don't let him pass, and to resist sin and temptation more and more.
“The Rosary is a powerful weapon to put the demons to flight and to keep oneself from sin…If you desire peace in your hearts, in your homes, and in your country, assemble each evening to recite the Rosary. Let not even one day pass without saying it, no matter how burdened you may be with many cares and labors.”
– Pope Pius XI
>“No one can live continually in sin and continue to say the Rosary: either they will give up sin or they will give up the Rosary”
– Bishop Hugh Doyle