About "Hosted Elements" output

About Hosted Elements,
just want to understand its 5 output terminology (inserts, shared, shadows, openings, walls),
what are these clearly stand for?

I can tell insert usually stands for doors and windows,
what get me confused the most is shadow, as image shown below…

See this post for a detailed explanation, with pictures and such.

So its clean now: “An internal WallShadowCutoutGStep is created when 2 walls are joined.”

So its clean now, but still strange those pink shadow windows are queried but they were actually from another host wall (not the red one).