The Layers panel is used to create new layers, to move objects between layers, or to apply attributes (like transparency) to a layer. To view the Layers panel, choose Window > Layers or press the F7 function key. Icons on the bottom of the Layers panel tell you how many layers you have in your document and allow you to:
• Make/Release Clipping Mask: Used when one layer acts as a clipping mask to reveal only part of an underlying layer.
• Create New Sublayer: Defines a layer within the selected layer.
• Create New Layer: Creates a layer at the same level as the selected layer. So, for instance, if you click this icon with a sublayer selected, you create a new sublayer (not a sublayer of the sublayer). ...