Working with layers : Duplicating and copying layers
 
Duplicating and copying layers
You can duplicate a layer within an image. You can use the duplicated layer as a starting point for a new layer, or you can try out edits and effects on the duplicated layer while keeping the original layer intact. You can also copy a layer to another image by copying and pasting or by dragging the layer into another image.
To duplicate a layer within an image
Edit tab 
Select the layer you want to duplicate, and choose Layers Duplicate.
The duplicated layer is added just above the selected layer.
You can also right-click the layer name and choose Duplicate.
You can also choose Edit Copy to copy the layer and then choose Edit Paste As New Layer.
To copy a layer to another image
Edit tab 
1 On the Layers palette, select the layer you want to copy.
2 Choose Edit Copy.
3 Open the image in which you want to paste the layer.
If the image has layers, click a layer. When the copied layer is pasted, it will appear above the selected layer.
4 Choose Edit Paste As New Layer.
The layer is pasted on the center of the canvas.
To copy a layer and drag it into another image
1 Choose the Edit tab, open both images.
2 In the Layers palette, drag the layer that you want to copy from one image to the tab of the other image, and when the other image becomes active, drop the layer in the position you want in the Layers palette.
The Edit tab must be in Tabbed Documents mode (Window > Tabbed Documents) to drag and drop layers between images.