I think first thing is to study REFramework itself, the documentation, and whatever documents available by “googling”. and maybe Academy.
Even just looking at this modified picture helps a bit, to understand the flow.
(I modified the LOOK, moved the boxes and arrows around, but technically didn’t change anything)
I think this way its easier to understand.
(I also think this is how they should use this layout it in a future update)
Much easier to understand if those arrows/transitions are not entangled like in the original.