A long time ago, France helped rule Cameroon, and sometimes they were very mean to people who wanted Cameroon to be free.
France and Cameroon worked together to look back at what happened a long time ago, and they wrote it all down in a big book.
The book said that France did bad things and hurt many people in Cameroon, a long, long time ago.
France said they were sorry for what happened, but they haven't said exactly how they will make things better yet.