iCloud

User is networking multiple Apple devices using the cloud and Handoff. He wants to retire his Macbook Air and give it to me. I am tasked with preparing it.

He thinks there are files on it that cannot be accessed from icloud.

Is there any way to verify this?

Am I correct in thinking once a doc or file is created and syncs to the cloud it can be accessed with any device on his network even if the device where original file is located is removed?

Thanks'