Specifically what parts you are not sure about?

Asking one to explain it while yourself does not address it in any way or any sense what is not understandable to you is like shooting in the dark. The merge explanation is thoroughly addressed by the Ethereum team itself, and there are many conversations about it that readdress it in a simple manner. Asking to explain it again would only give a burden to the explainer since one can not tells it in a specific manner of what you are trying to understand and which part you are trying to comprehend.