Arranging the Stacking Order of Layers
The arrangement of layers within your image is critical to what the
image looks like. If one layer is above another one, that layer’s data
can cover data below it.
To change the stacking order of layers—which changes the resulting image—move
layers on the Layer palette. If a layer or a layer group has components,
such as vector objects or group layers, all the components move with it.
To move one layer, layer group, or vector object:
On the Layer palette, click
the name of the layer, layer group, or vector object and drag it to a
new position. A black line shows the position until you release the mouse
button.
To arrange the stacking order,
either:
Drag the layer, to the desired
position. The cursor changes into a hand 
. If it displays
a null symbol 
, you cannot move the selected item to a particular
position. For example: The background layer cannot be moved. There can
never be a layer below the background layer. A vector object cannot be
moved in to a raster layer. Mask and Adjustment layers cannot be at the
bottom of an image or a layer group.
Choose Layers
> Arrange > and then choose either: Bring
to Top, Move Up, Move Down, Send
to Bottom, Move into Group,
Move out of Group.
To move multiple vector objects:
On the Layer palette, click
the first vector object.
Press Shift
and click each additional vector object, or right-click and choose Select
all.
Use the Layers > Arrange commands
or drag the selected objects to a new position. A black line shows the
position until you release the mouse button.
Moving Layers within
the Image Canvas
Merging Layers
Cleaning
up the Edges of Layers Created from Selections
Deleting Layers or their
Contents