The Overlays widget indicates the overlay where a member originates. Overlays serve a function similar to that of libraries in other languages.
Members in higher number overlays that match members of the same name in lower number overlays replace the lower number members.
Overlays that disabled are listed as grey.
The folder where the overlay is stored is displayed as a mouse hover and can be opened in the file explorer using Ctrl+Shift+E or the context menu.