No they are different things. CSAM detection is looking for specific images from a database before upload to iCloud photo library: https://www.apple.com/child-safety/pdf/CSAM_Detection_Techni...

The child protection part can be enabled for under 13s if they’re in a family account. If enabled messages app will try and detect adult images being sent and received and give a warning to the child, it can also let the parents know about it.