The parent commenter gave an explanation that, yes, was simple and concise, and also good enough for you to believe it (or you already thought that way). But it's also wrong. That just reinforces my point.

(The true difference is explained in sibling comments to yours, by sergeykish and tannhaeuser, if you're interested.)

The parent commenter explained it in a somewhat obtuse way.

I don’t doubt they meant to be clear, but reading it they were not and raised more questions than were answered.

As an example:

Wouldnt attributes be better served as details about the current element?

Wouldn’t elements be better served as “I am a child of the parent”?

Why would I use an attribute as a “non-repeating child” when semantically that doesn’t make sense when looking at the document? The attribute is inside the element’s definition, and seems to me attributes should be used to further describe the element being presented itself, and not be structural or describe itself as a child in any way.