Layers : Concept and when to use it
Principle and interest
The aim of the layers editor is to let you grouping your images as you want, for example by separating the panorama at the horizon level, to make a different color correction to the sky separately to the ground. It makes sense when stitching bracketed images, where each bracket level can be defined in separate layers, allowing direct blending or an export of each layer.
You can also use the Layers editor for other purposes. For example, sometimes the images are hard to find, so you can use the Layers Editor to find them (selecting an image in the Layers Editor selects and highlights it in the editing area)