Cutting, Copying, Pasting, and Deleting
Cut: Edit>Cut allows you to select a specific portion of the photograph and “cut" it out of the document. You can then paste the cut portion into a separate image or paste it into another portion of that image.
Copy: Copy is a lot like the Cut tool, except in this case it doesn’t remove the selected portion from your image. It will make a copy of the selection allowing you to paste it into another document or somewhere else on your already existing image.
Copy Merged: Copy merged is a great tool to have if you’re working with a document that has many layers. If you select a portion of your document and go to Edit>Copy, Photoshop is only going to copy what you have on the selected layer. Copy Merged will allow you to select and copy everything within your selected area from all layers.
Paste: Pasting allows you to place whatever you’ve selected and copied into your document. You can create a new layer and paste into the new layer, or paste directly onto your already opened image.
Paste Into Selection: Edit>Paste Into Selection allows you to take something you’ve copied and paste it into a specified dimension. You can move the pasted image around until you’re happy with where it’s been placed.
Delete: Delete works the same way as it would if you pressed the delete key on your keyboard. Rather than copying the selection or cutting it from the image and placing it on your clipboard, it deletes that part of the image from your photo.