Okay little one, have you ever been to a church before? You know how sometimes there is a book that the preacher reads from and everyone else follows along? That book is called the Book of Common Prayer.
It's a special book that has prayers and readings that people have been saying in churches for hundreds of years. It helps everyone know what to say and when to say it during the church service.
The Book of Common Prayer was first made in England over 500 years ago by a man named Thomas Cranmer. He wanted everyone to be able to understand the prayers and be able to say them in their own language, and not just in Latin like they used to do.
Nowadays, there are many different versions of the Book of Common Prayer used by different churches all over the world. It may look a little different in each book, but the prayers and readings inside are all very similar.
So, whenever you go to a church and see the priest or the congregation reading from a book, that's probably the Book of Common Prayer!