An angel, "messenger, messenger," is the name for eternal beings whose duty it is to serve God. Angels are spiritual beings, who do not have a body, but have their own personality and free will. Among all created beings, angels are the most capable and therefore the closest to God. They do not belong to our space and time, but they can act in our reality.
The role of angels is to glorify God and convey messages to people. There is a hierarchy of angels. One group of angels are called archangels, among whom the most famous are Michael, Gabriel, and Raphael, who are mentioned in the Bible, and Uriel, who is mentioned in the apocryphal writings.
In Catholicism, angels are of paramount importance. Pope Benedict XVI says: "Angels should be worshiped as much as Mary, without them many events from the Scriptures could not have happened."
Prayer to the Guardian Angel
Dear guardian angel, they covered me with their strength.
According to God's promise, keep me night and day.
In particular, it prevents me from being hurt by sin.
And when I leave this world, I am happy to come to heaven,
that there with thee I may worship the dear God for ever.