How to work with layers in 2.9x like in previous versions (2.7x) I'm trying to learn Blender using version 2.9.  I'm watching a tutorial from Blender Guru, Andrew Price, in which he uses an earlier version (tutorial made 2017).  This is the Anvil tutorial.  However I am trying to &quot;interpret&quot; what Andrew is doing on his version and how to do the same on 2.9.
A prime example of this is Layers.  In his Anvil tutorial he makes a duplicate anvil and places it on a spare layer for use later on in the &quot;bake&quot;.  This allows him to work on the first layer and keep the other for later.(High poly and low poly version)
In 2.9 I have found the box with layers in the top right.  I have tried copying to a new layer, but when I sculpt on the original one it changes the other layer too, which can't be the aim.
I can't seem to create the same actions in the latest version and run two distinct layers with different info on each.
The 2.7 Layers have been replaced by Collections, you should now use Collections. Basically one former Layer is now one Collection (and when you open an old Blender file Layers are automatically replaced by Collections).

You're confusing Layers with View Layers, which are completely different things, View Layers are useful for the Compositor (which is not the case in this tutorial).
With View Layers you're just changing the visibility settings of the current scene for later compositing purpose, so when you modify an object, it's the exact same object as the one of another View Layer.