The Cut Named command cuts the content of the selection from the active layer in the usual way, but instead of storing the contents in the global clipboard, it stores it in a special buffer that you name using a pop-up dialog.

The Copy Named command copies the contents of the selection from the active layer in the usual way, but instead of storing the content in the global clipboard, it stores it in a special buffer that you name using a pop-up dialog.

The Copy Visible Named command copies the content of the selection from all the visible layers in the usual way, but instead of storing the content in the global clipboard, it stores it in a special buffer that you name using a pop-up dialog.

The Paste Named command simply brings up the Buffers dialog. By selecting one of the listed buffers, and pressing one of the buttons at the bottom, you have several options to paste a buffer into the current image or as a new image.