Okay kiddo, let me explain what "Spiritus Domini" means. "Spiritus" is a Latin word that means "spirit" and "Domini" means "of the Lord". So "Spiritus Domini" means "Spirit of the Lord".
Now, Pope Francis recently issued a new document called "Spiritus Domini" which allows women to officially serve as lectors and altar servers in Catholic Mass. Lectors are people who read the Bible readings during Mass, and altar servers help the priest during Mass.
Before this document, only men were allowed to be altar servers and lectors in some parts of the Catholic Church. But now, with "Spiritus Domini", Pope Francis is saying women can also take on these roles.
The document explains that women have always played important roles in the church, and allowing them to serve as lectors and altar servers is a way to recognize and honor that. It's a big step forward towards equality in the church, and it shows that everyone is important when it comes to worshiping and celebrating God.