You can duplicate layers within an image or into another or a new image.
Drag the layer or group to the New Layer
button .
Choose Duplicate Layer or Duplicate Group from the Layers menu or the Layers palette menu. Enter a name for the layer or group, and click OK.
Drag the layer or group from the Layers palette to the destination image.
Select the Move tool , and
drag from the source image to the destination image. The duplicate
layer or group appears above the active layer in the Layers palette
of the destination image. Shift-drag to move the image content to
the same location it occupied in the source image (if the source
and destination images have the same pixel dimensions) or to the
center of the document window (if the source and destination images
have different pixel dimensions).
Choose Duplicate Layer or Duplicate Group from the Layers menu or the Layers palette menu. Choose the destination document from the Document pop‑up menu, and click OK.
Choose Select > All to select all the pixels on the layer, and choose Edit > Copy. Then choose Edit > Paste in the destination image.