Regina caeli is a type of prayer that is said by many people who are part of the Catholic Church. It is called Regina caeli because those are the first two words of the prayer in Latin, which is the language that the prayer was originally written in. When people say Regina caeli, they are asking Mary, the mother of Jesus, to help them and to watch over them. They are also praising Mary for the wonderful things she has done for them. Just like when we ask our own mothers for help, people who say Regina caeli believe that Mary will listen to them and help them when they need it.