On the bottom left, there’s the file system. That’s simple : These are files on the hard drive.
On the right, there’s the scene tree. I understand what that is.
But… What is the list of files in the red rectangle? They don’t seem to match the files used in the current scene (there is more in that list) and they don’t seem to match a specific folder of the resources either. What is that list?
This is the list of all script files that are currently open (i.e. that have been open and not closed at one point in time), regardless of the scene currently open.