Please Note: This component relates to legacy methods for drawing UI textures and images to the screen. You should use Unity’s up-to-date UI system instead. This is also unrelated to the IMGUI system.
A GUI Layer Component is attached to a Camera to enable rendering of 2D GUIs.
When a GUI Layer is attached to a Camera it will render all GUI Textures and GUI Texts in the scene. GUI Layers do not affect UnityGUI in any way.
You can enable and disable rendering GUI in a single camera by clicking on the check box of the GUI Layer in the Inspector.