Rhino 8: New detail on & model on

Can anyone explain what New detail on & model on mean in the layers panel?
I don’t understand “New detail on” at all. What does this do?

I am assuming “Model On” is the same as “Layout On/Off”, just renamed to add some clarity/confusion.

Hi @erikratliff,

See this:

Does this help?

– Dale

After watching Mary Ann’s video yes it helped. Took watching it a few times to get what is going on.