Sculpt Layer

Layers are used to maintain the original form of the object you’re working with.

You can make layers for texture/damage/detail and if you decide to make changes entirely or create a different look altogether you can remove the layers and make new ones while maintaining your original object.

Sculpt tree layers are for your voxels or surface mode object as you know already.

The layers panel at the bottom is multi-purchase.

1. In “Surface Mode” you can have non-destructive sculpting layers, The original sculpt layer object is not altered. Shown in the quick limited video but gives you the idea how it works.

Simple Example:
You have a head object completed. Now you can add wrinkles pores etc, non-destructively.
Plus you can add asymmetrical work to the head without altering the symmetrical base head model.  Sculpt layers are indeed powerful.

2. For surface mode or voxel painting. 

The above is not a tutorial or the best practice of using the layers panel mentioned above.

Side Note. Create a simple model and test the sculpt layers out to see how it works yourself.
Of course, you are not limited to fine details.

One thing to mention though is never use layer 0, it is for 3DC’s internal use.

When testing the paint mode be sure to select Under the paint room View menu > Show voxels in the painting room.
Your voxel or surface mode will disappear otherwise.

The SculptTREE panel indicates it is effectively a Hiearchy panel, much like the Outliner panel in Maya or 3ds Max.

The LAYER panel is just like Photoshop’s Layer panel. It stores paint information, as well as Sculpt/Depth information.

We often say “layer” in reference to an object in the SculptTree panel, because it’s the most descriptive name for it, because calling it an OBJECT would not be totally accurate, since you can have multiple objects on the same “Layer”.

So, I guess you would consider it an OBJECT LAYER.