Each Layer Set contains the same group of layers, all the individual layers created in a plan; and each layer set can show, hide and display those layers uniquely.
Saved Plan Views, Layers & Annotations
4 - Understanding Layers
5483 - Understanding Layer Sets
240 - Understanding Default Sets
2421 - Saved Plan Views
904 - Controlling What Displays in 3D
5435 - Using the Reference Display
5302 - Active Layer Display Options Side Window
