The Layers panel is a way to manage the layers in your document. Use the Layers panel to prevent overlaps, to change the visibility of layers, to nest or stack layers, and to select one or more layers.
Layers are displayed as a list of names, in order of z-index; by default, the first created layer (with a z-index of 1) appears at the bottom of the list, and the most recently created layer (with a z-index greater than 1) appears at the top of the list. You can change the z-index of a layer, however, to change its place in the stacking order. For example, if you created eight layers and wanted to make the fourth layer the "top" layer in the stacking order, you could assign it a higher z-index than all of the other layers.
For more information on using the Layers panel, see the following topics: